Presto Composition software by Dr Guerino Mazzola. English Documentation

Preface
presto is a new type of musical composition software for your Atari Computer. It was received by Herbert von Karajan with the historic words: "You could leave me alone a whole night long with it!" Thanks to his recommendation presto was realized on a commercial level.
With presto, it is the first time that the uncodified universe of sounds is in front of your eyes. Competence in score reading or instrumental skill are no longer indispensable conditions for a creative interplay with music, be it in composition, in arrangement or in analysis of music pieces.
What you are so easily controlling with your mouse is indeed the first, exclusive and user oriented application of geometric music theory which was initiated in 1979 at the University of Zrich. If there is interest in getting deeper into this theory, one may consult the book "Geometrie der Tne" by Guerino Mazzola (published by Birkhuser, Basel 1990).
Apart the possibility to create your music, you may as well load a MIDI file with preferred pieces and analyze, rearrange and shape them at will. How about Mendelssohn's "Wedding March" in gipsy major tonality, or Mozart's "Kleine Nachtmusik" in pentatonic tonality, with steel cans, marimba and flutes in c major, or Jimmy Hendrix' Purple Haze with strings and in a Messiaen tonality? No problem with presto!
Or else you may be a cellist in a string quartett, and you would like to learn your part. But you are having difficulties with the tempo for certain hard runs. Just take a MIDI file with your string quartett (such pieces are more and more available on the market), hide your own voice and set the tempo curve as you whish: Insert rallentandos and accelerandos as you like: presto will follow your most extravagant ideas. It will be the infini
tely patient correpetitor.
Suppose that you want to have support for composing musical configurations like rhythms, arpeggios, dodecaphonic or even serial structures. Then, presto will allow for unlimited access to these instances without making you worry about theoretical foundations or even mathematical theorems. A practically infinite variety of musical transformations is at your disposal.
And if it happens (it should should really do so!) that you are tired of well-structured processes: Just start drawing your chaotic and creative sound pictures with the mouse. If this seems to be too chaotic, you may still correct it by means of a freely set percentage of tonal, rhythmic or even two-dimensional altera
tion. In this way you control random instead of being a slave of it.
And - last but not least - presto is a sequenzer, i.e. a digital tape allowing for recording your pieces from a MIDI instrument or - simultaneously - from the movement of the mouse. You may record with or without any metronome, reject it, save it, record together with existing material, look at the result, correct the mistakes by tonal, dynamic, durational and rhytmic quantizing, and so on! And if you like it, take the recording to another sequenzer program by means of standard MIDI files, etc.

But as far as you are concerned with creative composition or (re)arrangement, the best is to stick to presto - there is no alternative!

We whish you much pleasure with presto!


1. INTRODUCTION

1.1 What you should know before you start working

1.1.1 Preliminary knowledge while working with Atari computers

If you want to work with presto, you should have basic knowledge of the handling of your Atari, mouse, keyboard and harddisk (if you have one). This has to be learnt by means of the correspon
ding manuals.

In particular, you should be acquainted with icons, menu and dialogue boxes, with mouse functions, loading, saving and dele
ting of files or programs via disks or harddisk.

To describe inputs, we fix the following terminology:

-The word "click" means "click with the left mouse button".
-An expression in square brackets (e.g. [Esc]) means that you have to press the corresponding key.
-An expression in pointed brackets (e.g. <Reset>) means the corresponding field on the monitor to be clicked. For your orientation, we always add the corresponding menu to the particular menu points, e.g. <File/Load> instead of "<File> in the file menu".

Some commands may also be given by special combinations of key strokes. You press the [control] (^) or [alternate]	(folder symbol) together with the corresponding letter.

All dialogue boxes which have a small square field in the right upper corner may be moved around while holding down the mouse pointer on the square field. 

1.1.2 Preliminary knowledge of MIDI devices

The kowledge of handling MIDI devices like synthesizers and expanders at your disposal has to be learnt by the corresponding manuals.

In particular, you should be able to set the sounds and their configurations if you are not restricted to using presto commands concerning MIDI channels and program changes.

In chapter 6, you will find the necessary hints concerning the MIDI standard and its application within presto.


1.2 System and installation

1.2.1 Computer, disk and harddisk

To run presto, you need an Atari computer of type ST, STE or TT as well as a high resolution black and white monitor (640x400 pixels, i.e. pictural points). From now on, we simply write Atari for one of the above types. The files may be saved on ordinary 3.5" disks or on a harddisk. On a double sided disk (720'000 Bytes), roughly 80'000 notes can be saved, a quantum correspon
ding to the content of six scores of classical string quartetts, or one CD.

Let us suppose that you have installed correctly your Atari, that it is ready to operate, but not yet switched on.


1.2.2 Key, program and demonstration disk

The kernel of presto is written on the key included in the manual. It gives you a very good protection of the presto program.

Please make sure that the Atari is switched off, otherwise you risk to destroy it! Insert the key in the cartridge slot, the Beethoven picture looking upwards.

The program periphery is contained in the program and demonstration disk. This disk is to be exchanged for updates while the key remains yours.

The demonstration disk contains files in the presto format (extender .STO) to be used as exercise material, as well as the README.TXT file containing some important stop-press information and recommendations concerning the MIDI instrumentation of demonstration pieces for different synthesizers.


1.2.3 MIDI devices

Connection of a MIDI instrument to be played for MIDI recording on presto: Connect the MIDI in port of Atari with the MIDI out port of the instrument by a MIDI cable.

Connection of MIDI instruments to be commanded from your Atari: Connect the MIDI out port of Atari with the MIDI in port of the first instrument by a MIDI cable. Connect the MIDI thru port of this instrument with the MIDI in port of the second, and so on. If using several MIDI instruments, the use of a MIDI thru box is recommended.


1.2.4 Audio equipment

Make sure that the audio ports of all the MIDI instruments are correctly connected to your audio equipment. Use a mixer if working with several instruments.

Make sure that all control elements are in good position.


1.2.5 Getting started

AThe key is inserted in the cartridge slot (c.f. 1.2.2).

BInsert the program disk in drive A.

CSwitch on all devices, the Atari at last.

DAfter the appearance of the desktop, open drive A.

EMake sure that the RAM has at least 500 free kBytes.

FDouble-click on <PRESTO.PRG> and presto gets started; the main display appears.


1.2.6 Quitting presto

Before leaving presto after work, make sure that the pieces you want to keep are saved on disk or harddisk.

Click the menu point <File/Quit>, and presto will be closed. The desktop reappears.

While working with other programs, your presto key may be left in the cartridge slot. Please switch off the Atari before removing the key, otherwise you risk to destroy the computer!


1.2.7 Contacts with the manufacturer in case of problems

Please refer to chapter 7 for trouble shooting. If you have further problems or questions, please don't hesitate to contact the manufacturer by phone, fax or letter. The coordinates are indicated in the impressum at the end of this manual.

Of course, the manufacturer is interested in getting your feedback whatsoever.


1.3 The concept

The presto concept makes possible much more than catching ready-
made music by a digital tape protocol and making a desktop edition of it. It enables you to produce your music creatively, to modify it or simply to take a precise look at and to analyze it. Thereby, the artificial limits of traditional notation and of instrumental skill are eliminated. This meets all those music lovers who don't like reading scores or playing an instrument. The presentation of sounds in presto is new and - at first sight - somewhat intriguing. But everybody will become well acquainted with it after a few minutes. And it will become clear that the transparency and precision of this presentation is ideal for composing.


1.3.1 Geometry of sounds

A sound is completely described by five attributes: 1) Onset time; 2) Pitch; 3) Duration; 5) Instrumental colour.

Within conventional musical notation which refers to traditional instruments, these attributes are codified and not always uni
quely determined. They are a sketchy notation of music. Onset and duration of a sound are only defined via relatively vague tempo indications and within the concrete context. Loudness (mezzoforte (mf) etc.) and instrumental colour (violine, piano etc.) are defined in an extremely rough sense connotating instrumental practice.

In contrast, today's electronic instruments (synthesizers, drum
computers etc.) allow for a precise and complete control of sound attributes. The MIDI standard introduced 1983 (see chapter 6) is a codex of digital sound processing permitting a direct control of sound parameters by a computer. By this, the conventional notation doesn't loose its historic significance, but it simply doesn't meet the actual technological potential any longer. The latter allows to transcend the mere sketch and to create complete compositions including their interpretational delicacy.

Under these circumstances, a new, simultaneously precise and lucid presentation of sounds and compositions is required. It is expected that it includes as well the musical shapes as the syntactical aspects of music. The access to musical shapes is guaranteed in presto by presenting sounds as "coloured" points in a big geometrical space. Since we are restricted to black and white monitors here, the colours are indicated by different iconic symbols for the different instrumental colours. The position of such an icon in the geometric space corresponds to the four geometric attributes (numerical parameters) onset, pitch, duration and loudness.

Though we present the sounds as living in a four-dimensional space - and musicians really always do that in a more or less codified way! - there is a wunderful, simple and intuitive method allowing to work exclusively on the two-dimensional monitor! It amounts to forget temporarily two of the four attributes and to work in the plane of, say, onset and pitch. Then, we may change the plane by concentrating on two other parameters and operating from another "perspective". The guarantee that you can get all those far out things which can be done in four-dimensional space, is given from results of modern mathematics. It is these wunderful results which are integrated in presto without troub
ling you with annoying formulas and the like.


1.3.2 Three scenarios: Global score, score and local score

In prsto, a composition appears as beeing a configration of "coloured sound points on a geometric landscape". From the musicological and the practical point of view, this "geographical" representation is ideal to create compositions, to arrange and to analyze music.

Sometimes, one wants to see the whole and takes charts of large scale: This bird's perspective is given on the global score.

Or else one wants to look at parts containing several hundert sounds and therefore picks the chart of medium scale: the score.

Finally, one may wish to look at small portions of the actual composition. In this case, one chooses the local score, a perspective where the work and study of every detail is possible.

These three scenarios are simultaneously at your disposition so that you will never loose the control. You may also define the charts by blocks like with text programs (in the score) or even arbitrary polygonal regions (in the local score).
             This musical geography is completed by the possibility to hide any part of the instrumental icons and to activate them again if the work on the active icons left is done.

As soon as the work on any of these perspectives is done, you may merge the result with the larger context.


1.3.3 Input: Load from a file, recording, drawing

There are three different ways to define the input of sounds in persto. Either you load a composition given as standard MIDI or presto file from a music library on disk or harddisk. Or else you use presto as a sequenzer and record your composition via a MIDI instrument (keyboard, MIDI guitar, MIDI saxofon etc.) or via the mouse, with or without metronome. Or you use the mouse to draw configurations of sounds.

These three input modes may join or complement each other, which means that you may choose in every moment the best approach.


1.3.4 Music library

A music library for presto is beeing established.

It consists of disks containing pieces of different styles saved in presto forma (extender .STO). On one hand a classical repertoire will be set up in order to allow for an intensive, active and interactive study of given compositions. You may also use the MIDI files on the market.

On the other hand, elements of music, like melodies, rhythms, chords etc. will be available. The requests coming from presto users will essentially determine this spectrum of elements. Please let us know your desires!


1.3.5 Working modes

A composition in consideration may be modified in various ways depending on the chosen scenario. Let us give a summary of working modes: Block operations as they are known from text programs, i.e. moving, copying etc.; Boolean operations on sets like union, intersection, difference of sets of sounds; choice and combination of instruments to define orchestrations, change of orchestrations at any time in local and global domains; defini
tion and modification of tempo curves by the mouse; quantizing of onsets and other parameters; correction with respect to particu
lar tonalities, e.g. in order to eliminate recording errors; transposing, inverting and retrograde; creation of general orna
ments, in particular to generate rhythm patterns; gradual attrac
tive and repulsive deformations of compositions according to given ornaments; rotations, dilatations, reflections and all the transformations of serialism; scissoring for arpeggios and cres
cendi, general transformations by graphical definition via mouse - and all this without using mathematical formalism.


1.3.6 Output: Save and play

An entire composition or parts of it and of its instrumental icons may be played and listened to. The content of the global score or any block may be saved as standard MIDI file or as presto file on 3.5" disks or on the harddisk.


1.4 Survey


1.4.1 The function scheme

The function scheme (take out the second copy from the manual for general orientation while working) shows the three scenarios global score, score and local score as as "spine", on which different functions are acting (arrows). As secondary scenarios, we have six registers where sketchy parts of the compositions of the score or the local score may be stored.

The blocks are arbitrary parts of the global score to be defined by any beginning and end.

The play boxes show that you may listen to the respective music parts in any scenario.

The input via files or via recording by MIDI instruments resp. mouse acts on the global score, whereas drawing acts on the local score. The state of the score is automatically taken over to the global score, but that of the local score and of the registers is independent of that of the (global) score.

Between score, local score and the registers, the different composition parts may be combined according to boolean set operations at will.

The choice of active instrument icons acts on all scenarios. The setting of a new orchestration automatically acts on the local score, it may be inserted into the global score on the level of the score.

The tempo is defined graphically-interactive by the mouse and is shown as a curve below and on the level of the score. The metronome (for recording etc.) regulates the tempo on the global score.

Symmetries and ornaments, in particular corrections of tonality and quantizing, act on blocks as beeing parts of the global score.

The drawing and colouring operations on the local score level act within the chosen parameter plane. The remaining two, momently hidden, parameters and the instrumental colours are defined before drawing. For the colouring operation an arbitrary polygonal region is defined in order to modify the sounds within this region with respect to their hidden parameters or sound colours. Or else this region may be moved, copied or erased at will; its sound configuration may also be played.


1.4.2 First run on the example of a demonstration file

Before discussing the single scenarios and the corresponding operations in detail, we offer you a first impression of the special features of presto by means of a presto file which you may load from the demonstration disk.

We suppose that you are already running presto and that the main display with global score, score and the registers is on the monitor. The demonstration disk is in drive A.

-Click on <File/Load> and choose the file HASCHEMA.STO containing Schumann's "Hasche-Mann" from "Kinderszenen" op.15.

-In the middle of the global score, you can see a black sector. Move into the slider below the global score with the mouse pointer. Hold down the left mouse button and drag the slider until it stays below the black sector and release the button.

-On the score, you can see the Schumann piece.

-Recall the MIDI channel and the program number of your sythesizer where you have a (classical) piano sound.

-Click on <Instruments/Orchestration>.

-Click into the number filed below "CHAN" to the right of icon number 1. Press [Esc] and write the channel number of the piano sound.

-Click into the number field to the right of the first number field, press [Esc] and write the program number of the piano sound. Click on <OK>.

-Go in front of the begin of the piece (left to the piece, time runs horizontally from left to right) with the arrow of the score slider.

-Drag the field <O> on the right below the register of the local score into the score above the score slider and release the button. Now, your orchestration is defined in the score from the new vertical orchester line on.

-Click on <Play> above the score; the presto data are now converted into MIDI data and a dialogue box appears; click <Start> and you will hear the piece without delay.

-Below the score the tempo is visualized. In order to recognize it precisely, double-click on the tempo field. Now, the tempo curve is activ and may be treated graphi
cally.

-Now, the position of the mouse pointer is given by cross
hairs. Go between two adjacent points of support of the tempo curve; a click generates a new point of support.

-Go exactly  onto the new point of support (take sight exactly, otherwise you generate another point of support) with the pointer and hold the left mouse button pressed. If you see a small white cross in the point, you are ok.

-Now, you may pull this point around and the curve will be deformed like a rubber band. Move the point down vertically and release the button.

-Move the pointer to the left of the V on the tempo curve you just produced and move it vertically upwards or downwards till you leave the tempo field. A new pointer with a small "Play" within appears. Click and the piece will be played from that moment on. You can hear the extreme rallentando you have defined.

-The piece is written in B minor. We want to alterate it to B gipsy major. Click on <Ornaments/Create>.

-Click on <Tonalities> in the new dialogue field.

-A new dialogue field shows 16 scales and the 12 possible tonics. Click on <Gipsy major> and on <B>. Confirm with <OK>.

-Click on <Composition/Score>.

-Move the arrow of the score slider in front of the piece and drag the field <M> on the left below the register of the local score into the score above the score slider and release the button.

-Confirm the following question about generating a new motif on the dialogue box.

-Hold [Alternate] and pass over the whole piece from the left to the right with the mouse pointer: a corresponding block is defined.

-Click on <Ornaments/Alteration> and then click <up>.

-Shortly after this command, the piece is alterated to the new gipsy tonality and you may listen to it as indicated above.

-Now, move the score slider to the left until it includes the begin of the piece. Double-click on the score above the slider. You get the same part in the zoomed presentation of the local score. You are in the parameter plane of onset (horizontal coordinate) and and pitch (vertical). If you want to see the durations of the sounds, just click on <Instruments/Piano roll>.

-Click on <Set transform>. Click on the icon with the vertical line to the right of "Reflect" within the following dialogue field (it will be inverted). Now, click <Reflect>. Click on any point of onset value 35 within the local score to the left. You have chosen a vertical reflection.

-Click on <Local score>, you get back the well-known working field of the local score. Click <Colouring> and then <Inverse>. Both fields are inverted.

-Move the pointer to a region without sounds. Click the left and then the right button. Click <Transform>: Your part on the local score is vertically reflected.

-Click on <Play>: You can hear a retrograde version of the local score piece.

-Click again on <Set transform>, click the icon of horizontal reflection and then <Reflect>. Click on any point in the local score field to the left having pitch value 44. You have chosen a horizontal reflection.

-Click again on <Local score>, and you get the well-known local score.

-Repeat the procedure as done for vertical reflection above and your piece is reflected horizontally at pitch 44.

-Click on <Play> and you will hear the inversion of the retrograde.

-Now, click on <Onset/Pitch> and hold the button down: The pulldown menu opens, you move to <Onset/Loudness> and release the button. This changes your parameter perspective to the plane where horizontally, you have onset and verti
cally, you have loudness instead of pitch.

-Click on the highest (loudest!) sound point in the left upper corner. Encircle the highest row of point with a polygonal region. To do so, just click every time you wish to define a new vertex of the polygon. If you arrive near the starting point, click the right button and the polygonal region is defined; the starting point of your polygon is marked

-Now, click on <Move>. In order to move the contents of the polygonal region, position the pointer some units above the starting point and click.

-Click on <Play> to be sure that now, some notes are played louder.


2. PRESENTING MODES OF SCENARIOS

2.1 Sounds

2.1.1 Geometric, MIDI - and physical attributes

Classical notation of sounds means a command to operate on an instrument, e.g. to strike a key. The physical sounds produced in this way depend on the parameters of the instrument. With MIDI instruments, the MIDI command will have an effect in function of the setting of the MIDI commands within the instrument. Since - as pointed out above - classical notation is not precise enough to define MIDI commands and since such commands (sequences of O and 1) have no musical meaning, the attributes of sounds are represented as being coordinates within a geometric space with a clear musicological significance. This looks as follows.


2.1.2 Pitch

In presto, sounds have the attribute of pitch, a number from 1 to 71. The number 71 has been chosen for several reasons, see section 4.4.3.2 for details. The pitch numbers are taken to the key numbers 27 to 97 (see chapter 6). For the usual well-tempered tuning, pitch 1 corresponds to D#1, pitch 2 to E1,... and pitch 71 to d#4, i.e. the middle six octaves of a 88-key piano.

If the tuning of the MIDI instrument is changed, the meaning of the pitch numbers is also altered. With drum synthesizers, the number will, in general, mean a definite drum sound. See also chapter 6.


2.1.3 Loudness

In presto, like pitch, loudness is given by numbers from 1 to 71. This skaling corresponds to the stretching factor 128/71=1.8028 of the MIDI scaling of velocity from 0 to 127 (see chapter 6). See 4.4.3.2 for a justification of this scaling in presto.


2.1.4 The time attributes

2.1.4.1 Musical and physical time

The conventional notation uses durations like quarters, eigths, pointed eigths etc. The onset of a note with respect to that of the others is determined (more or less uniquely) by the relative position within the musical text and relative to bars. But it is only the tempo (e.g. M.M1/4=120, i.e. 120 quarters per minute, M.M. means Mlzel Metronom) which allows to define the physical times involved. Without the M.M. indications, a quarter note is only a relative value. Further, a computer cannot divide infini
tely the duration values; in reality, each value is a multiple of an elementary pulse or "tick".

In the conventional situation, the user needn't care about this fact. He may leave the problem of time resolution to the machine. But in presto, it is possible to mix the time coordinates with other parameter values like pitch and loudness when operating with transformations. For instance, a rotation of 90 degrees in the plane of onset and pitch will transmute time values into pitch values and vice versa. If, in this situation, quarters are transformed into half tone steps, eigths correspond to quarter tone steps, a refinement of the given MIDI command which your MIDI device wouldn't understand. And if it could do so, you would suddenly be confronted with microtonal scales (nothing really upsetting, indeed), and our listening habits would probably be irritated.

Therefore, time is quantized by "ticks", the onset units 1,2,3,...Of course, you may still go on thinking within the usual frame, the metronome is at your disposal. But you will always see sounds as being points with time coordinates being inserted within the elementary grid of onsets.


2.1.4.2 Onset, duration and tempo

For a sound, presto offers two time coordinates besides pitch and loudness:

-Onset: It may vary from 1 to 11'360, the length of the global score.

-Duration: It is a multiple of onset units from 1 to 71.

For the MIDI codex the onset corresponds to the Note-ON command, whereas duration is the distance between Note-OFF and Note-ON. Note, however, that only the tempo really makes MIDI commands out of onset and duration values wich are part of the symbolic music notation! In presto, you may visualize durations when activating the <Instruments/Piano roll> representation showing the duration as length of a horizontal beam. But you may as well choose a purely geometric representation of sounds showing them as points (with iconic shape in the local score). This latter representa
tion has the advantage that for graphical purposes, overlapping of beams will not disturbe the sight.

Further, the symmetry of representation of sound parameters is not disturbed, an important condition while working with trans
formations of sound configurations.

Corresponding to this time representation, the tempo also refers to onsets. The tempo curve below the score indicates for each onset, how many onsets per minute we actually have. Thereby a very sensitive tempo differentiation is guaranteed. It is the musicologically justified means to create a human and expressive tempo (including finest rubato effects) out of mechanical tempo presets. This makes it obsolete to use any of those questionable so-called "humanize" effects. You may see the power of the tempo curve from the Schumann Kinderszene "Der Dichter spricht" (op. 15).


2.1.5 Instruments

Besides the four geometric attributes onset, pitch, duration and loudness, every sound has the attribute of sound colour. This is symbolized by numbers 1 to 16 and is shown by a small icon on the local score. To each icon, you may associate channel and program change numbers (corresponding to the settings in your synthesi
zers). Within the global score, you may redefine this setting as often as you want (see chapter 3).

This means that, on the gemetrical level of presto, each sound is given by an iconic point within a four-dimensional geometric space, and that, to each such iconic point a MIDI event on your synthesizer(s) is associated.


2.2 Global score

2.2.1 Active instruments

The global score contains all informations of the composition in consideration. Sometimes, it is useful to work or to hear only a subset of the 16 instrumental icons. For this, you hide the icons which are momently not interesting or disturbing. You may change this selection at any time. Anyhow, when saving, all icons are taken into account.

Call the hidden icons the passive ones, the others are the active icons.

Hiding and activating of icons is done by click on the icons above the global score.

Active icons are marked by a check.

It is recommended to remain within the frame containing the icons while defining the passive and the active ones. In doing so, you prevent the main display from being redrawn too often.


2.2.2 Occupied sectors

The global score serves for visual survey. You recognize it as a long, narrow strip, whose horizontal extension represents onsets from 1 to 11'360 (=20x568), each pixel for a portion of 20 onsets; 1-20, 21-40 etc. till 11'341-11'360. If there is one sound of an active icon within such a portion, a black strip of one pixel width appears. This gives you the desired survey.


2.2.3 Play

Below the global score, you see a slider which can be dragged horizontally: Move the pointer into the slider, press down, hold the button and move the slider. When releasing the button and pressing <play> above the global score, the entire global score from the beginning of the score slider to the end is played as soon as you press <Start> on the subsequent dialogue box. For interruption, click the right mouse button.


2.3 Score

2.3.1 Choice of the score sector

The position of the slider of the global score determines the sector of 568 onsets shown in the score.


2.3.2 Active instruments

The set of active instrument icons (2.2.1) is also valid for the score; you only see the sounds of active icons.


2.3.3 Sounds

2.3.3.1 Graphical representation

In the score, the sounds of active icons are drawn by squares of 3x3 pixels with light centre. The horizontal position of the inner (light) pixel is the onset, the vertical one indicates pitch, duration or loudness depending on the choice within the pulldown box on the left above the score. Though with this representation, adjacent sounds may graphically overlap each other, the image is clear and allows for good positioning of the sounds.


2.3.3.2 Pulldown for vertical parameters

Pitch, duration and loudness are the vertical parameters in the score representation and may be chosen by the pulldown on the left above the score. Their values 1-71 correspond to 71 pixel steps. When choosing the pitch, we get an image comparable to a normal score, with the advantage that you see the real distances.


2.3.3.3 Pitch, duration and laudness

If the vertical parameter is pitch or loudness, the duration can be red by activating the piano rolls. Nonetheless, exact recognition of parameters ist best done within the local score.


2.3.3.4 Onset

The onset is divided into 568 horizontal pixel steps. You may read its value from the number on the right above the score. The value is defined by the position of the arrow of the score slider. You have to move the cursor on the score to the centre of the sound whose onset you want to know.


2.3.3.5 Tempo

Below the score, the tempo is indicated. Double-click on this field, and the tempo field is activated. It is a polygonal curve whose horizontal coordinate is the onset of the above score. The position of the pointer (crosshairs) is indicated on the right above the tempo field: first the onset, second the tempo value (onsets per minute). To maintain orientation, the vertical part of the crosshairs is extended to the score. The tempo values move from 32 to 4240. This allows for a time resolution from 1/2 to 71 onsets per second.

The tempo scale in vertical direction is shown in logarithmic scale. This means that transposition of tempo by a determined value will multiply all tempo values by a determined factor. This operation will be explained in 4.3.2.5.

To set new support points of the tempo curve, click on the intended position. To erase a support point, press the right button, hold it and move the vertical line of the crosshairs over the point to be erased.


2.3.3.6 Position of the cursor in the score

As long as the music goes on, a cursor moves along the sounds you are hearing. When interrupting, the cursor stops moving and remains visible in order to show the final position. The score is not rebuilt during playing.


2.3.3.7 Metronome

The metronome above the score indicates the beginning of the bars (long vertical marks) and the positions of the metre (short vertical marks). Suppose, for example, that you have defined a 11/17 metronome (this works!). Then all the 1/17 marks are short and every eleventh mark is long. The relation to the grid of the onsets is defined by the resolution chosen within the metre. Suppose that your resolution of a 1/17 is 3. Then, each 1/17 is three onsets of length, and the length of one bar 11x3=33 onsets.

   2.3.4 Orchestration

If there is a change of orchestration within your composition, then you can see this by means of a corresponding vertical line in the score. The old orchestration is valid to the onset preceeding this mark, the new one is valid from the onset of the mark up to the next orchestration mark.


2.3.5 Play

If you click on <Play> above the score, then the score sector from the position of the arrow of the score slider is played as soon as you press <Start> in the subsequent dialogue box. You interrupt with a click on the right button. The time delay (normally it is only one, two seconds) is due to the integration calculus for the MIDI ONs and OFFs by means of the polygonal tempo curve.

If you modify the tempo, you may immediately listen to the results if proceeding as explained in 1.4.2.

If the metronome is activated (see 5.1.4), you can hear the ticks of the metre, the beginning of a bar being a higher tick. These ticks stem from your monitor speaker and have nothing to do with your synthesizer.


2.4 Blocks

2.4.1 Setting and clearing of block marks

Blocks are sectors of a composition on the global score including all sounds between two onsets, the beginning and the end (larger than beginning). In order to set the beginning, you move the slider of the global score to get a rough position, you position the score slider to the beginning and you click on <Block/Begin>. You repeat this procedure to define the end and you click on <Block/End>.

You may also define a block by passing over a sector of the score with the pointer. If you start over the score slider, please hold [Alternate] pressed down. You may displace the bords of a block by pressing [Shift] and moving the pointer near one of the bords.

If you have defined the block, the sector between the marks will appear inverted.

Within a block, you can execute the operations on sounds and tempo described in 4.3.

If you have defined a block, there is a <B> to the left of the score <Play>. If you don't need the block temporarily, click on <B> and the block is hidden. Click again in order to redefine this block.


2.4.2 Play

If a block is defined, the score <Play> will make you hear the contents of the score.


2.4.3 Time information within blocks

Within a block, you can read the physical time interval from the beginning of the block to the position of the arrow of the score slider in hundredth of seconds.


2.5 Register

Below the score, there are six registers A-F and one register for the local score. The representation of sounds within these registers is the same as in the score. The onset interval is 71 units, i.e. the registers are squares, a selection which has advantages while working in the local score (see 4.4.3.2). The possibilities and goals of data combinations between score, registers and local score as well as their tempos and orchestra
tions are explained in 4.2.


2.5.1 Register A-F

The musical contents of these registers is taken from the score or the local score. Above all, they serve as intermediate memories, test areas and for quickly listening short compositon sectors.


2.5.2 Register for the local score

The contents of this register is identical with that of the local score. It is above all useful to transport the contents of the local score to the score.


2.5.3 Play

You can hear the music in a register with a click on <Play> below that register.


2.6 Local score

2.6.1 Opening and closing the local score

You can open the local score with click on <Composition/Local score> or with double-click on the register of the local score (without changing the contents of the local score!). With a click on <Score>, you leave the local score and turn back to the score.


2.6.1.1 Bar and metre

Wile opening the local score, you can see the bars and the marks for the metre above the local score field. The number of the first bar is indicated above the vertical keyboard.


2.6.1.2 Piano rolls

The piano rolls are also visible in the local score if activated by a click on <Instruments/Piano rolls>. The piano rolls are only visible on the parameter planes given on the score level since they don't make sense on other parameter planes.


2.6.2 Parameter planes

It is the philosophy of the local score to treat in complete symmetry the four geometric parameters of sounds, a requirement wich has its musicological reasons and which is of eminent practical use.

The local score has six parameter planes corresponding to the six possible couples of parameters out of the four candidates: onset, pitch, duration and loudness. In each plane, you work on a 71x71 square with values from 1 to 71.

In the upper right corner, the pulldown box allows to define the plane of your choice. The first parameter is the horizontal coordinate, the second is vertical. After that choice, you see the sound configuration in the local score from the perspective of that particular couple of parameters. Within the local score field, you may move with the cross-hairs to every sound icon and read their two parameter values (relative to the parameter plane of your choice) in the right bottom corner.


2.6.2.1 Onset/Pitch

In this parameter plane, the horizontal coordinates are 71 onsets, the vertical ones are 71 pitch values (1-71). To the right of the field of the local score, you may directly read the pitch from the keyboard. The middle c is the key c of the piano (c1).

In contrast to the values of pitch, duration and loudness, the onsets are only of local character.


2.6.2.2 Onset/Duration

In this parameter plane, the horizontal coordinates are 71 onsets, the vertical ones are 71 duration values (1-71).


2.6.2.3 Onset/Loudness

In this parameter plane, the horizontal coordinates are 71 (relative) onsets (1-71), the vertical ones are 71 loudness values (1-71).


2.6.2.4 Duration/Pitch

In this parameter plane, the horizontal coordinates are 71 durations (1-71), the vertical ones are 71 pitch values (1-71) which you can also read from the keyboard to the right of the field of the local score.


2.6.2.5 Loudness/Pitch 
In this parameter plane, the horizontal coordinates are 71 loudness values (1-71), the vertical ones are 71 pitch values (1-
71) which you can also read from the keyboard to the right of the field of the local score.


2.6.2.6 Loudness/Duration

In this parameter plane, the horizontal coordinates are 71 loudness values (1-71), the vertical ones are 71 durations (1-71).


2.6.3 Instrument icons

In the local score, you can see the sound points as being small icons, the symbols of the sound colours of the present orchestra. Hence, you always know, which instrument you are working with. To the right of the field of the local score, you can read the names of the instruments if you have defined them (to do so, see 3.2).


2.6.4 Active instruments

As with the global score and the score, you may temporarily hide any subset of icons. This affects all scenarios. The passive icons are invisible and are not taken into account for any operation on the active icons. If you want to make active/passive an icon, please move the pointer to its field to the right of the local score field. Here, there are three states:

1	white, without check,

2	white, with check,

3	inverted, with check.

With every click on this fields, the state changes cyclically:

1	means passive,

2	means active,

3means active and ready to draw with this icon (see 4.4.1 for this point).

If you want to hide/activate several icons at once, please stay within the frame around the 16 icons with the pointer. presto will notice all your changes and execute them together after your action. This prevents the program to rebuild the screen more than once.

The combination of the six parameter planes and of the sets of active icons allows you to see everything you want to know about the present local score contents.


2.6.5 Setting and clearing of marks of colouring polygons

The colouring polygons correspond to the blocks on the level of the local score, but they are far more general in shape. We shall see in chapter 4 that you can produce very subtle effects by use of such polygons.

To set a colouring polygon, you choose a parameter plane and a set of active icons. Then you click on <Colouring> and the field is inverted. Now, you click on an arbitry point of the local score field. You get a first fix point of the polygon, together with a flexible straight line. Move the pointer to a second fix point, click, and you may go on as you like. If you click the right button, the last fixpoint will be connected to the first one and the polygon is constructed. Its inner part will be darkened. If you are more interested in the outer part, please click <Inverse> above <Colouring>, the field is inverted. Click again if you want to clear the inverse mode. Please pay attention to this modality since you may be working on the wrong side of the polygon!
 In order to clear the marks of a polygon, please click on <Colouring>. (To draw, click once again on <Colouring>, the field will return to normal state, see 4.4.1 for detail on drawing.)

In order to capture all sounds of the local score composition, click left and then right on a point which is no sound (such a point is always at disposal!). Then, you invert this mini colouring polygon with a click on <Inverse> and you have done with it.

The same left-right click method may be used to define a one-
point polygon, e.g. for a single sound.


2.6.6 Play

If no colouring polygon is set, the contents of the local score is played after a click on <Play>.

If a colouring polygon is set, only its contents is played after a click on <Play>. This has the great advantage that you may hear very complicated subsets of sounds you are interested in, e.g. a particular chord, melody etc.

3. ORCHESTRATION

3.1 Assignment of MIDI channels to instrument icons

If you want to define the sound colour of the 16 icons, click on <Instruments/Orchestration>. In the column "CHAN", you can write the MIDI channel number (1-16). You may use the same channel number for different icons. The advance of this setting is that if you are momently working with one instrument, you are nevertheless prepared to split it up into different ones later.

The default numbers coincide with the icon numbers.

If you set 0 as channel number, the icon is muted.


3.2 Assignment of program change numbers and instrument names to MIDI channels

In the column "PROG", you can set the number of the program change number (1-128) of the channel of the icon. The meaning of this number is a function of the settings in your synthesizer(s), see also chapter 6.

In this column, the default is number 1.

The MIDI standard does not allow to define different program change numbers on one and the same channel number. If you try to contradict this rule, presto will define the orchestration in such a way that the program change number of the first icon with a given channel number is copied to the other icons with the same channel number.

In the field to the right of the CHAN column, you can write names of maximal length 10 for your instruments.

Click on <OK> or <Cancel> in order to confirm or to reject the new settings.


3.3 Validity range of an orchestration

The orchestration which you have defined through <Instruments/Orchestration> is automatically valid on the local score, it is a local orchestration. If you want to transfer this orchestration to the global score, you move the score slider to the onset which is the beginning of the new orchestration. Now, you drag the small square <O> below the score register to the score above the score slider and release the mouse button. Or you double-click on <O>. There are two possibilities now:

1) If there was no orchestration mark above the arrow of the score slider, you directly get such a mark which defines the validity range of the new orchestration from this mark to the next orchestration mark (or up to the end of the global score if this mark is the last one).

2) If there already is an orchestration mark (2.3.4) above the arrow of the score slider, you get a dialogue box with three possible decisions: Either you replace the old orchestration by the new one, or you cancel the old one without setting a new one, or you cancel the whole action.

Attention! For onset 1, you evidently cannot cancel that orche
stration mark, it is only possible to replace it.


4. OPERATIONS ON FILES AND SCENARIOS

4.1 Operations on files

4.1.1 Reset

A click on <File/Reset> erases the total contents of the global score:

-No sound is left.

-The tempo is reset on 512 onsets per minute.

-The metronome is not audible, the bar is 4/4, M.M.1/4=128, and resolution is 4 per 1/4 (see 5.1 for details).

-The orchestration is defined by a orchestration mark at onset 1 with the default of the orchestration data (see chapter 3).

In contrast, the contents of the registers is not altered - except tempo and orchestration wich are those of the reset, see 4.2.2-4.2.7 for register data.

The contents of the local score is maintained except the tempo which is modified like for the registers. But the local orche
stration remains inaffected.


4.1.2 Load

If clicking on <File/Load>, you get a dialogue box, where a file with presto extender .STO can be loaded as usual. If loading a file, the global score is replaced by the new file to the same extent as resetting (4.1.1)! To the left above the global score, the name of the file is shown.


4.1.3 Merge

The menu point <File/Merge> supposes that there is some free place (without sounds) on the global score, where you may place sounds of a new file. To do so, fix an onset with the arrow of the score slider as being the start of the file to be merged. Then, click on <File/Merge> and choose the file.

After confirming with <OK>, the new file is merged (together with its tempo, metronome and orchestration data since they are saved in the presto format, see 4.1.5) from the above starting point on. Merging stops one onset before the next sound of the already existing file. (Orchestration and tempo are replaced as long as no sound appears!)


4.1.4 Merge MIDI

If you want to load a MIDI file (standard MIDI file format, extender .MID), click on <File/Merge MIDI>. Except for the tempo, this procedure is identical to that of 4.1.3. The difference for the tempo is that the existing tempo within the free region of the global score remains valid while merging MIDI files. If, for instance, the tempo is 480 onsets per minute, the MIDI data are inserted with a resolution of 8 per second. The synchronization of MIDI data with onsets is defined as follows: The first MIDI event of your file coincides with the arrow of the score slider. This allows you to create a resolution of MIDI events which fits with your desires.

You can merge standard MIDI file formats 0 and 1. Besides the data of this manual, merging also reads names of instruments. - Onset and duration are quantized. The transformation factor between MIDI time and presto onsets is determined at the beginning of the piece (arrow of score slider). The time relations of the MIDI file are only reproduced 1:1 if the tempo is constant (horizontal tempo curve). If merging sequencer-
generated files, the constant tempo is appropriate, whereas merging of presto-generated file requires the same tempo you used while creating that file. - The instruments of the MIDI file are distributed one after the other on the active icons. If there are several tracks, they are treated in ascending order. If the icons are all used, merging stops. Attention: Merging MIDI resembles to recording together with the playback of a given global score piece. This makes merging MIDI to something different from simple (.STO) merging!

Merging MIDI respects channel and program change numbers, Note-ON and Note-OFF, Key and attack-velocity; other MIDI commands are lost since they cannot be transformed (for transformations, see 4.4.3) without destroying their natural meaning. We refer to chapter 6 for further information about MIDI commands.


4.1.5 Load transforms

In the menu point <Compositions/Transformation chains>, lists of transformations and their combinations can be defined (4.4.3.8/9) and saved (4.1.8). Such lists can be loaded via <File/Load transforms>.


4.1.6 Save

If clicking on <File/Save>, you may save the contents of the global score as presto files (extender .STO). If a block is defined (and active, inversed, see 2.4.1), you are asked whether you want to save everything or only the block.

Saving and loading of presto format has the advantage to be faster than MIDI format and that in addition, tempo, metronome, channel and program numbers as well as names of instruments are saved.


4.1.7 Save MIDI

If you click <File/Save MIDI>, your global score resp. an active block is saved in standard MIDI file format 1. Only those sounds whose onset and end time (=onset+duration) are contained in the block. Use piano rolls to check this (2.6.1.2). It is important to know that information about the tempo curve gets lost, that the physical time information is preserved and that you may load this type of file in other programs like normal sequenzers.

The MIDI commands which are saved are identical with those which are loaded.


4.1.8 Save transforms

You can save the actual list of transformations and transforma
tion chains which you have defined via <Composition/Transformation chains> if you use the extender .TRA.


4.2 Operations between score, registers and local score

4.2.1 The sectors of compositions on which operations take place

The following relates to composition sectors of 71 successive onsets each, as they are defined on the six registers A-F and on the register of the local score.

Further, you may also define such a sector on the score via score slider.

All the operations in 4.2 can be cancelled if clicking on <Undo> or [Undo].


4.2.2 Replacement of the local score

Choose a sector of the score by use of the score slider. Via left double-clicking, the local score is replaced by this sector, and you simultaneously enter the local score display.

The orchestration of the local score is replaced by the orchestration which is valid in the score sector defined by the slider. The tempo is equally replaced by that tempo.

Via left double-click on a register, you may equally replace the local score contents by those of the register, including tempo and orchestration of that register.


4.2.3 Create combinations

Everything that follows in 4.2 relates to two composition sectors of 71 onsets each as described in 4.2.1. The first of these sectors is called start window, the other is called target window.

Click the start window and hold the button down while dragging the start window to the target window. Release the start window when arriving over the target window. Then, a dialogue box appears which offers four different operations (4.2.4-4.2.7) - unless you cancel these option.


4.2.4 Union

Here all the sounds of the two windows are united. Observe that a sound of the start window completely unites with a totally identical sound of the target window.

Tempo and orchestration of the union are those of the target window.


4.2.5 Intersection

With this operation, you only keep those sounds which are identically existing in both windows.

Attention! Since you only see one parameter plane at once, two sounds may appear to be identical though they differ in their hidden coordinates. Hence they may be eliminated from the intersection.

Tempo and orchestration of the intersection are those of the target window.


4.2.6 Difference

Only those sounds are preserved which stem from the start window but are not contained in the target window: The target window is "subtracted" from the start window.

Tempo and orchestration of the difference are those of the target window.


4.2.7 Replacement

Thereby, the start window replaces the target window.

Tempo and orchestration of the replacement are those of the score if the target window is on the score, otherwise they are those of the start window.


4.2.8 Applications of these operations

4.2.8.1 Security copies

Replacement (4.2.7) of a register by the (register of the) local score or with a window of the score can be used to create security copies of important local sectors.


4.2.8.2 Hearing test

You can replace several registers with sectors of the global score to quickly compare their contents without moving around in the global score.


4.2.8.3 Combining of composition sectors

You may combine sectors on registers for a test and insert the result in the global score as soon as you like it.

Further, according to 4.2.2, you can replace the local score with a sector of the (global) score, add new sounds etc. and replace the old sector on the (global) score by the modified one. Observe that the position of the score slider should be the same as before!


4.3 Operations on blocks

4.3.1 Text-oriented operations

4.3.1.1 Move

In order to move a block defined according to 2.4.1, you go to the new onset, where the beginning of the block is to be positioned. Then click < Block/Move> and the complete content of the block is inserted. This operation also moves passive icons.

In order to preserve the tempo around the block in its old position, two support points are inserted.

The orchestration marks within the block are equally moved. In order to preserve orchestration at the beginning of the block, you should define one at its beginning before moving. The same idea is valid at the beginning after the block in its old and new positions!


4.3.1.2 Copy

To copy a block defined according to 2.4.1, you go to the new starting point of the copy with the score slider and click on <Block/Copy>. At this position, the same happens as with moving the block. The difference is that the old block remains were it was, too.

The contents of the global score is shifted to the right by the length of the block. Observe that, if doing this, sounds risk to be shifted beyond the end of the global score, the copy cannot be created. Then, you have to decide to eliminate (4.3.1.4) or to empty (4.3.1.5) certain blocks or sounds.


4.3.1.3 Union

In order to unite a block defined according to 2.4.1, go to the onset where the block should be added to the existing material of the global score. Then click <Block/Union>. Like with the union of two registers 4.2.4), the given (start) block and the sector of the length of the given block from the score slider on (the target block) are superposed. Tempo and orchestration are those of the target block.


4.3.1.4 Elimination

You can eliminate a block defined according to 2.4.1 if clicking on <Block/Eliminate>. Thereby, the global score to the right of the block is attached to the part to the left of the block. In order to maintain the tempo around the block, two support points are inserted at the borders. In order to maintain the orchestra
tion after the block, you should insert an orchestration mark just after the right border of the block.

Attention! By this operation, sounds on passive icons are also removed!


4.3.1.5 Empty

You can empty a block defined according to 2.4.1 by clicking on <Block/Empty>. The tempo is not affected by doing so. Only the sounds with active icons disappear. Orchestration marks disap
pear, hence you should set an orchestration mark right after the block if you want to preserve the last orchestration of the block for the subsequent sectors.

In particular, you can eliminate a part of your icons from the composition if you just empty the disturbing icons and tempora
rily hide the good ones.


4.3.1.6 Flatten tempo

In order to flatten tempo within a block defined according to 2.4.1, click <Block/Flatten tempo>. Then, a dialogue box gives you two possibilties (besides cancelling): Either you reset the tempo to a constant value for the total block, or you flatten it in the sense to destroy all its support points and to make it to be a straight line between two new support points at the borders and in a position where the old tempo crossed the borders.


4.3.2 Symmetries

4.3.2.1 Transposition

According to your choice (2.3.3.1/2.3.3.2), you may shift upwards or downwards pitch, duration or loudness of the sounds within a block between -99 and +999. To do this, click on <Symmetries/Transposition>. To transpose downwards, click on the spot to the left of <inverse>. For example, you shift one pitch unit upwards in order to transpose a piece from C major to C# major. To the right of the dialogue box, you are offered three possibilities of treating sounds which move too high or too low (Overflow): Either you delete these sounds (Delete), or you let them reappear on the opposite border (Rotate), or you let them stop at the upper or lower extremity (Maximum). Everything apart the parameter to be transposed is left as it is. Confirm your choice by clicking on <OK>, reject with <Cancel>.


4.3.2.2 Inversion

If you click on <Symmetries/Inversion> for a block defined according to 2.4.1, the pitch (resp. duration resp. loudness) of the sounds of the block is reflected at pitch (resp. duration resp. loudness) 36. This means that pitch 36 remains fix, 35 goes to 37 etc. In the case of pitch, this is the traditional inversion. When inverting twice, you get back the original.

If you want to invert at another pitch, just invert and add an appropriate transposition by 72 minus this other pitch (resp. duration resp. loudness). If. for example, you want to reflect at pitch 13, you invert and add a transposition by 72-13=59. The overflow is <Rotate>, here.

In musicology, this symmetry is called real inversion in the case of pitch since the semitone distances of the sounds are preser
ved. In contrast to this, there is the tonal inversion which only inverts the pitch as being a multiple of the distances within the given tonality.  You may construct a tonal inversion by use of ornaments, see 4.3.3.7, example B.


4.3.2.3 Retrograde

If you click on <Symmetries/Retrograde> for a block defined according to 2.4.1, the block is reverted in its time direction. This symmetry is called "retrograde".

The tempo is reverted, too. Hence, an accelerando is changed into a rallentando - and vice versa.

Pay attention to the fact that the retrograde is not a simple reflection of two onsets! It only affects the onsets of the sounds. To begin with, the onsets are reflected, then, for each reflected onset, the duration of the corresponding sound is subtracted from the onset, defining the correct new onset of this transformed sound. In this operation, only those sounds are transformed whose onset and end time (=onset+duration) are contained within the block.  You may check this with the piano roll (click <Instruments/Piano roll>).


4.3.2.4 Retrograde of inversion

To execute the retrograde of the inversion on a block, just execute retrograde (4.3.2.3) and then inversion (4.3.2.2) (or conversely, the order is irrelevant in this case). Observe that for the classical retrograde of inversion, the pitch is needed as vertical coordinate!


4.3.2.5 Tempo transposition

Instead of shifting sounds vertically (transposing) for a block defined according to 2.4.1, you may do the same thing with the tempo curve within a block. Since the vertical coordinate of the tempo is scaled in logarithms, vertical shift means multiplica
tion by a constant factor, a musically reasonable operation.

To do this, click on <Symmetries/Tempo transposition>. In the following dialogue box, you write a multiplication factor from 00.01 to 99.99. If the factor is for division, click on the spot to the left of <inverse>. Then confirm with <OK>. Under this operation, support points which would lie beyond the limits of our tempo field, are only shifted to these limits (32-4240 onsets per minute).


4.3.3 Ornaments

Ornaments are classical structures in fine arts and applied arts. You can see them on greek vases, on floors, walls of historic and modern buildings, on textile and wallpaper. Music also uses orna
ments, but normally, you do not see them because they operate in time. In presto, this very useful technique is implemented in its full range of power. If you are accustomed to it, you will never again do without it.


4.3.3.1 The block

As with all other block operations, a block defined according to 2.4.1 is activated. All the following ornament operations (4.3.3.4-4.3.3.9) presuppose that you are given a block. But you may apply an ornament, consisting of motif and displacement grid, to different blocks.


4.3.3.2 How to create the motif and the displacement grid

A presto ornament has three ingredients: the motif, the (displace
ment) grid and the (displacement) range of the ornament.

The motif is something like the flower pattern for a wallpaper which is repeated in a regular fashion. In presto, this motif is either the present contents of the local score (local motif) or the contents of an arbitrary block (block motif).

How far and in what direction the local or the block motif is to be repeated on the global score, this is determined via click on <Ornaments/Create grid>. If you do so, you can see the local motif to the left in one of the three possible parameter planes onset/pitch (resp. /duration resp. /laudness) of the local score. Observe for the following that this refers to the position in the global score, where the local score was taken from. If you have chosen to work with a block motif, this cannot be seen as a whole. But the following works on the same principles.

Now, you click on a first point in order to mark the starting point of two independent displacement arrows (vectors) within the chosen parameter plane. The arrow-head of the first arrow (= horizontal displacement) is determined by a click on a second point, the arrow-head of the second arrow (= vertical displace
ment) is defined by a click on a third point. If you want to restrict to only one displacement, you just position the third point onto the first one. You may position the three points anywhere on the global score. To do so, just choose the score slider to lie in a position where the first point will lie and double-click: This will define a local score in the right position, i.e. you may go to the grid creation field as indicated and position the first point there. Then, you return to the global score, choose a new position of the score slider and duble-click again: you will directly find yourself in the grid creation field in order to position the second point. And so on for the third point. If you want to see the grid parallelogram spanned by the horizontal and the vertical displacement, click on <Ornaments/Show grid>.

Now you can displace the motif by multiples of the two displace
ment arrows according to a multiplicity to be defined now. Here, positive multiples are in direction of the arrows, negative multiples are in the opposite direction and quantity of the arrows. To fix these ranges of horizontal and vertical displace
ments, see 4.3.3.3.

The coordinates of the horizontal resp. vertical displacement are seen to the right in the grid creation field. Observe that "horizontal" and "vertical" are merely intuitive terms; we just suppose that intuitively, the first arrow is in time direction, the second in vertical direction. But the directions of the arrows are absolutely arbitrary! And the common starting point of the two arrows is not relevant at all, only the arrows themselves are relevant since they mean displacement quantities. Nonethe
less, it makes sense to position the arrows in the context of the global score since they often are defined using information about the relative position of certain sounds of an existing composi
tion.

If you don't like the arrows, you need only position a fourth one, and this one will be the first of a new couple of arrows.


4.3.3.3 The displacement range of an ornament

To complete the definition of an ornament, we have to fix A) the parameter plane wherein the ornament will be built, B) from which starting position and C) how often the motif will have to be displaced within the global score.

A) The parameter plane of the ornament is fixed according to (2.3.3.1/2.3.3.2). The grid will operate on this plane, even if you have defined the arrows on another plane!

B) In order to fix the starting position of the motif, please return to the main display. By a movement of the score slider, you fix the starting onset of the motif. If your motif is the local score, you drag the small square <M> to the score over the score slider. When releasing, an affirmative answer to the following dialogue box will fix the starting point of the local motif. If your motif is an active block, click on <Ornaments/Block motif> and an affirmative answer to the follo
wing question will do the same with the block motif.

It should not bother you that you cannot see the motif. This relates to the fact that ornaments have different functions to be explained in 4.3.3.4-4.3.3.8.

By the way, you needn't fix the starting position already now, you may also do it shortly before doing a concrete application of the ornament.

C) Now, you click again on <Ornaments/Create>. You consider the field for the range of horizontal displacement and insert beginning and end of the range by two entire numbers, the left one not larger than the right one (e.g. [0,4]). Do the same for vertical displacement (e.g. [-1,2]).

What is the meaning of these numbers? You just defined, how often the motif will be displaced by the horizontal and by the vertical arrows: In our example, you may displace the motif from 0 to 4 times by the horizontal arrow and, independently from -1 to 2 times by the vertical arrow. (The number -1 means that you displace the motif once in contrary direction to the horizontal arrow, 0 means not to displace.) This gives totally 5x4=20 displacements (the original position included) which we unite to an ornament.

Of course, this ornament may contain sounds which lie beyond the limits of the global score. These points are cut away. Now, the ornament is ready to operate! It still is invisible but, as already indicated, this is reasonable since it will have very different functionalities.

In order to save a composition block for the following operations of ornaments, please make a copy (4.3.1.2) or save it as a block (4.1.5). Notice that the block motif a priori is something completely different from the composition block whereupon the ornament will operate!

You leave the grid creation field by clicking on <Compositon/Score>. If you still haven't positioned your motif on the global score, do it now!

Interruption: If you will have presto running any of the following operations (4.3.3.4-4.3.3.8), in order to interrupt, press the right button and answer the question on the following dialogue box.


4.3.3.4 Intersection

By this operation, every sound of the composition block is erased if its two coordinates of the chosen parameter plane are not part of the ornament. The hidden parameters are ignored in this operation. To execute it, you click on <Ornaments/Intersection>.

Musically, this operation serves for eliminating sounds you don't want to save; often, such an ornament is given by a tonality (4.3.3.7). Thereby, you can eliminate all sounds whose pitches don't lie within a given tonality.

With the following trick, you may eliminate all pitches you are not interested in: Define a local motif on the local score by drawing (4.4.1) a big chord on the left border which contains exactly the pitches you want to preserve, the icon may be anyone of the active icons.

Now, you create a displacement grid by a horizontal arrow of length one and a vertical arrow of length zero (put the third point on the first 4.3.3.2).

The range of horizontal displacement is [0,x], where x is at least the length of the compositon block; the vertical range is [0,0]. Then, you place the motif onto the starting position of the composition block and you click on <Ornament/Intersection>.


4.3.3.5 Union

With this operation, the ornament is united with the contents of the composition block. Only now, the ornament becomes part of a composition. To do so, click on <Ornaments/union>.

There is a musically important application of this function: the creation of patterns which are periodic (cyclic) in time like ostinatos of basses or drum patterns. They generalize the forma
tion of loops known from normal sequenzer and drum programs.

The motif is any pattern which you want to repeat several times.

As a horizontal displacement, you choose a really horizontal arrow whose length is the period of repetition of the pattern; the vertical displacement arrow is zero.

The horizontal displacement range is given by the quantity of repetitions of the pattern, the vertical one is [0,0].

By means of uniting several of these ornaments, you may create very complex and exotic polyrhythms.

If you want to compose within a bar structure, you have to observe the periodicity of the bar, of course.

In particular, you may define very general "metronomes". Just choose an appropriate drum sound and create a nice metronome by differentiation of the different loudnes values (see 4.4.1 for drawing sounds). After having used the metronome, you may hide it or even empty (4.3.1.5) the global score from this supplementary structure.


4.3.3.6 Alteration

In music, alteration means that you slightly alter pitch upwards (by sharp or double sharp) or downwards (flat or double flat). In presto this central musical idea is at your disposal in a far reaching multidimensional generalization: it is the essence of the ornament operation.

With respect to this operation, we only need to consider the two parameters chosen to define the visible parameter plane of the global score. All other attributes of sounds are not afflicted by this operation. By the alteration, every sound within the defined block is "pulled" to a sound of the ornament lying near the given sound. This happens by means of a spiral which start in the given sound point and moves clockwise until it hits the first sound point of the ornament. In principle, the given sound is moved to this new position. If the spiral movement is not successful in finding an ornamental point after 32 turns or if the given sound is already contained in the ornament, then the process leaves the sound where it is.

In order to execute the alteration, you click on <Ornaments/Alteration>. The following dialogue box gives you the choice of starting the spiral one unit above, below, to the right or tho the left of the given sound. Click <Up> or <Down> or <Right> or <Left> if you want to make this choice.

The reason of these four possiblities is that you can determine, whether your sounds have the preference to be pulled upwards etc. This kind of choice generalizes the classical alteration into prescribed scales, where one shifts a pitch upwards (sharp) or downwards (flat) in order to move into the next position within the scale (see 4.4.3.7).

In the left lower corner of the dialogue field, you may insert percentage numbers from -999% to 9999%. This means the following: By 100%, the given sound is exactly pulled onto the ornament sound found by the above spiral movement. By 0%, the given sound remains unaltered. By all the other settings of % numbers, the given sound is moved on the straight line connecting the given sound and the 100% sound by the amount of the chosen percentage (of course the amount is quantized according to the entire numbers of the parameter space). For instance, the -100% altera
tion is a repulsive movement! The sound is moved away from the ornament sound found by te spiral. Except the 100% alteration, we will not move onto an ornament sound.


4.3.3.7 Tonalities

If you click <Ornaments/Create> and then <Tonalities> on the new display, a dialogue box appears, where you may choose one of 16 scales and one of the 12 possible tonics (C, C#, D,..., B) of a tonality.

This action defines a local motif of an ornament. It consists of all sounds of a tonality within an octave and with onset equal one on the local score (duration is 1, loudness is 36, the instrument icon is the one inverted on the orchestration field of the local score. If you click on <OK>, you get back to the dialogue field for creating grids, and you may see the motif. You can also hear it if <Instruments/Listen> is active (check). Here, you recognize that the horizontal and the vertical displacements are a horizontal arrow of length one resp. a vertical arrow of length twelve.

This guarantees that horizontally, every onset contains the ounds of that tonality, and that vertically, every octave represents the same choice of the scale.

The horizontal validity range is set to be [0,568] whereas the vertical one is set to be [-6,6]: this guarantees that for an onset length of a score, every octave is hit by the tonality in question.

These ranges can be altered already within the dialogue field of the tonalities.

Now, you proceed like with general ornaments: drag the <M> square to the score above the score slider and choose a block if this hasn't been done before.

It is recommended to define the dimensions of the block in a way that it lies between the borders of the validity range of the ornament (4.3.3.3). This ensures you that the ornament operations really do influence all the sounds of a block.

If now, you click on <Ornaments/Intersection>, all the sounds of the block (within the validity range) are eliminated which don't belong to the tonality chosen above.

Please, don't click on <Ornaments/Union>: this is a musical nonsense! Interrupt by a right click if you have already started.

If you click on <Ornaments/Alteration>, the sounds are not eliminated but shifted upwards or downwards to the next pitch within the chosen tonality. This special effect coincides with the traditional situation of musical alteration (sharps and flats). The onsets are not altered. If you don't chose 100%, it may happen that you only pull certaion sounds within the new tonality, a very subtle effect!  With negative percentages, sounds of your composition may even be repulsed from a given tonality.

Suppose, for example, that your composition in the block comple
tely lies in C major. If you choose the ornament for C melodic minor, you have to replace the pitch E by the pitch E flat.  All sounds except those with pitch equal to E already lie in C melodic minor. Where is E to be moved? If you click 100% <up>, E is alterated to F. If you click <down>, E is alterated to E flat, the movement which is intended by musician's ideas.


Four examples to begin with:

(Remark: Alterating means alterating 100% if no further specification is given.)

A. Change of tonality

Suppose that, for example, you are given a sector of Beethoven's Fifth written in C minor on the global score. Suppose that you want to listen in G locrian. Then you have two non equivalent possibilities.

The simpler one is musically less subtle: You just alterate into the new tonality. Then, you disregard the reference of the harmony with respect to the tonic C and relate everything to the new tonic G.

The better method amounts to transpose the piece by 7 semitones (4.3.2.1) and after this, you alterate to G locrian.  But try, and you will hear the difference!


B. Tonal inversion

In 4.3.2.2, we had discussed the horizontal reflection at a fixed pitch, i.e. the "real" inversion. With presto, the tonal inver
sion can also be executed. Let us illustrate the general idea with an example. Suppose that you want to make a tonal inversion within C major at the pitch E: This means that E remains fixed and that D and F, C and G, B and A are exchanged.

Since the distance from E to C is four semitones, that of E to G only three, real inversion at E would send C to G# instead of sending it to G etc.

In order to get the tonal inversion, it is sufficient to alterate downwards the real inversion to C major! This strategy is successful for major, minor and for all medieval modes (dorian etc., see dialogue box for tonalities).


C. Further tonalities

Beside the preset tonalities, you may define new ones at will. To do so, you go to the local score and select the parameter plane <onset/pitch>. You define a tonality, i.e. an octave of a scale starting from the tonic as it is suggested from the given tonalities. Then, you choose a grid and the validity range according to 4.3.3.7.

Remark: You may also define still more general tonalities if passing to a more general pitch period than the octave (=12 semitones). For instance, if you take 13 semitones for your extended octave, you get the situation suggested by Wyschne
gradsky!


D. Alteration of a composition A by x% "towards" composition B

Use the piece B as a block motif within a grid and a validity range where everything is zero and position the block motif at the beginning of piece A. Now, you choose a percentage X in order to alterate A to B by that quantity. Observe that the durations within the two pieces corrspond to your requirements. In order to accommodate them to each other, you may use time dilatation (4.3.4).


4.3.3.8 Quantizing

If you click on <Quantizing> in the dialogue field for creation of grids (menu <Ornaments/create grid>), you will create an ornament in the following dialogue box, which is analogue in time to what are the tonalities in the pitch, except that quantizing is simpler.

Quantizing means that we alterate onsets in time direction to the left or to the right with respect to a time grid.

You may set a quantizing number from 1 to 71. It indicates the length of the horizontal displacement arrow. If you want, you may create quantizing periods of arbitrary length, see 4.3.3.2, the method is to use grids of arbitrary size.

Since, normally, every pitch (resp. duration resp. loudness) is quantized by the same quantity, the vertical displacement is a vertical arrow of length one, and the motif is a single point of pitch (resp. duration resp. loudness) one and onset one; the respective other parameters are irrelevant, here. The validity range of displacement may be defined at will, like with the other ornaments.

If, for example, you take the quantizing number 16, your ornament will consist of vertical lines which appear every 16th onset from the starting point of the motif (in front of our imagination).

If you let the quantizing ornament operate on a block, and this normally is only reasonable with <Alteration/Left> or <Altera
tion/Right>, then, all sounds within the block will be pulled to the nearest onset in the quantizing ornament, all other parame
ters remain inaffected. By choice of variabled percentage of alteration, you may weaken or even overdrive (more than 100%!) the quantizing effect.

This principle underlies all quantizing programs. But it is only with presto, that you have the possibility to control quantizing in such details. In fact, you may even create a more general quantizing motif by taking a horizontal string of points in suitable relative position instead of a single point: you just turn the motif of a tonality by 90 degrees, that's the idea!


4.3.4 Time dilatation

If a block is defined, you may expand or compress onsets together with durations by a factor (1,2,3,4,...) by clicking on <Symmetries/Time dilatation>. If you want to expand by a fraction a/b, you may expand by a and then compress by b, but pay attention: there will be inevitable quantization effects since onsets and durations don't admit fractional quantities! The dilated piece will sound as before since the tempo will be multiplied with the same factor. The reason for dilating time is that the time resolution is refined. This is useful for fine alterations by general percentages. If you want to alterate a composition A into a composition B as in example 4.3.3.7 D, you should create a suitable metrical congruence of A and B by dilatation.


4.3.5 Changing icons

If a block is defined, you may click on an icon within the icon box over the global score. Then, a dialogue field opens to allow you to change all icons within the block marks and within two arbitrary values of the vertical parameter of the global score. This operation is a special case of changing instrumental colours (4.4.2.5) on the local score, but within the larger frame of the global score. Attention! If no block is defined, this operation is executed on the total global score.


4.4 Operations on the local score

4.4.1 Drawing

4.4.1.1 Activating instrument icons

If you are in the local score and want to draw sounds, first choose an instrument icon you want to draw with. As explained in 2.6.4, you put that icon on activity state 3, i.e. you click on the icon field till the field is inverted.


4.4.1.2 Hidden parameters

Now, you have to decide, on which of the six parameter planes (2.6.2) you want to draw. Choose this plane on the pulldown menu in the right upper corner (2.6.2). The two hidden parameters of the chosen parameter plane will not be variable when drawing. You have to set them in the right lower corner, where the four parameter values are shown. Click on one of the hidden-parameter fields, set the value and click [Return].

You may change these values at any time after having drawn a certain portion of sounds.


4.4.1.3 Setting and erasing sounds

Drawing sounds works as you imagine: Set them by clicking on the field of the local score. If you hold down the left/right mouse button and move around, you will set/erase sounds everywhere, where there is/isn't place.  The density of these effects depends on the velocity of your movement. Observe that for the onset/pitch plane, vertical lines may define excessive chords, whereas horizontal lines define mere repetitions of sounds. If <Instruments/Listen in> is active (check), you can hear the sounds in the moment you are drawing them.

If you want to set a sound where there is already an icon, either change the parameter plane or temporarily hide that icon and draw with another icon or draw a sound on a free place and move it (4.4.1.4) to the occupied place, there are always means to do what is logically possible!

A sound is erased with a right click. Observe that while erasing a sound, you will also erase all sounds hidden behind that icon. Hence, if you want to be sure, first hide all the icons which are not considered. Then, by change of the parameter plane, you can easily find out whether there are several sounds hidden behind your candidate. A very precise method of erasing a sound runs as follows: Put the local score to a register. Empty the local score and set a single sound with precisely those parameters you are looking for. Then take the difference of the local score copy on your register and the local score with that single sound (the latter being the target window, see 4.2.6). The same works with several sounds at a time.


4.4.1.4 Moving single sounds

If you want to move a single sound on a parameter plane of the local score, move the pointer onto that sound and hold the button pressed while you drag the sound to a new place. Observe that you will move all sounds having that position on the parameter plane.


4.4.2 Colouring

All operations which you can do on a colouring polygon strictly concern the sounds contained in this polygon (darkened part). If <Inverse> is active (inverted representation), the outside of the polygon is defined instead of the darkened inside (see also 2.6.5).

In order to prevent yourself from deceptions, please make a copy of precious local score situations on a register.

You may revoke every operation on a colouring poygon by clicking on <Undo> or [Undo].


4.4.2.1 Moving on the torus

If you want to move the contents of a colouring polygon, please pay attention to the starting point of the polygon (2.6.5). This is best done if you put this point onto a sound which you know where to move. Suppose that you have defined a polygon. Click on <Move>. You can observe that the starting point is marked. Then move the pointer to the new position where the starting point of the polygon has to go and click in that position.

In order not to loose sounds, we decided to  let sounds come in  from the right if they move out to the left and vice versa. The same is valid for upper and lower transgression of the borders of the local score.

In reality, we are working on a torus: Upper and lower borders of the local score square are glued together; then, left and right borders of this tube are glued together. This torus structure is valid for every parameter plane.


4.4.2.2 Copy

The procedure of copying the contents of a colouring polygon is the same as for the movement (4.4.2.1), except that the original contents remains alive, too. The position of the copy is determined in the same way as with the moving procedure.


4.4.2.3 Erase

After defining the colouring polygon (2.6.5) (pay attention to the <inverse> state!), double-click on <Erase> and the contents of the polygon is erased.


4.4.2.4 Hidden parameters

You may carry the value of a hidden parameter (4.4.1.2) onto the sounds within a polygon, i.e. "colour" them with this value. To do so, define the value as explained in 4.4.1.2, then, define the polygon, then click on the field with that parameter.


4.4.2.5 Instruments

You may "colour" the sounds within a polygon with a new icon if you click on the field of that icon, the state of that field is irrelevant. This serves for changing the instrumental colour of a part of your composition. But you may also use this method for putting aside a part because it disturbes you with regard to a determinate scope.


4.4.2.6 Transform

If you want to transform the contents of a polygon, click on <Transform> and the transformed content of the polygon is united with the rest of the local score.

The symmetries of retrograde (4.3.2.3) and inversion (4.3.2.2) are examples of transformations.

We shall see in a moment (4.4.3) what transformations are and what this universal tool is good for.


4.4.3 Transformation

4.4.3.1 What are transformations?

To work with presto and, in  particular, in order to manipulate transformations, you needn't have mathematical knowledge. Nonetheless, it is not the philosophy of presto to hide the operations to the user (like those programs offering black-box and random manipulations). It is erroneous to believe that the human part of music lies in the dark or is of random character; it is much more resident within a differentiated control of the parameters, every instrumentalist knows that.

Only those who comprehend the way their music was created can be good composers or musicians. Therefore, we would like to give a short introduction to the philosophy of transformations.

A transformation is a procedure which changes a given configura
tion of sound into another. But this is not to be done in a chaotic way. It should be granted that the geometric relations among the sounds are preserved: We require that sounds which lie on a straight line before transforming, still do so after the transformation.

You will be informed about the fundamental musical meaning and the different applications of transformations in 4.4.4.

With presto, you may execute all transformations in the four-
dimensional parameter space where the sound points lie. And this - we repeat it - will be possible without any mathematical specialization!

The recipe is simple: Choose  one of the six parameter planes of the local score. You will see the sounds as lying on a plane, the hidden parameters being invisible: forget about them at this moment. Click on <Set transfom>. The following dialogue field shows the local score on the left in the chosen parameter plane.
 If you have set your transformation, you have to go back to the local score (click on <Composition/Local score>!) in order to proceed as described in 4.4.2.6.

There are three strategies to define a transformation. Why? Because there are different musical situations suggesting the way how to set the input for a transformation. The three strategies are described in 4.4.3.3-4.4.3.5.

Observe that you may also change the parameter plane of the local score after having defined the transformation, it will always operate on the present parameter plane!

You may interrupt your definition process for a transformation: click on <Interrupt> and start again.

You may build a stock of transformations (see 4.4.3.8). This is at your disposition in the local score if you click on the pulldown menu with default setting <draft>. To activate one of the transformations of this stock, you needn't leave the local score.


4.4.3.2 Why a 71x71 field?

First: With respect to pitch, our choice has the advantage that we get about six octaves (72 semitones), an extend of many keyboards.

Second: If you don't want to make the icons to small (we take 5x5 pixels as a frame), the screen of 400x640 pixels suggests a number 400:5=80 similar to our choice.

Third: Since we treat all parameters in a symmetric way, the parameter field should be quadratic. 
Fourth: The precise number 71 is no mystic decision. It is a prime number having nice properties. As you know, our local score field represents a torus (4.4.2.1) in order not to loose sounds when operating. If we took 72 instead of 71, a horizontal stretching by factor 3 would throw two onsets of distance 24 onto the same point since 3x24=72, a distance which is set to be zero on the torus! Something like this cannot happen with the prime number 71. It guarantees that most of the transformations will not identify two different points - no information is lost. Please read 4.4.3.3 for further advantages of the number 71.


4.4.3.3 Standard transform with a fixed point

This first strategy is the most important in practice. Here, you have to set a point remaining fixed under the transformation. There are four types of standard transformations:

1. Reflect. You can reflect horizontally, vertically, at the diagonal and at the co-diagonal. Click on the corresponding icon. Then, click on <Reflect>. Finally, you choose the fixed point by a click on that point in the local score field on the left.

2. Whirle. By a click on the arrows of the whirle field, you may whirle up to 24 times. Whirling is  a kind of rotation on the torus. It is possible by the choice of the number 71, recall 4.4.3.2. If you whirle 6x, 12x or 18x, this means precise counter clockwise rotation by 90, 180 or 270 degrees. Whirling 24 times doesn't move anything.

After setting the whirling quantity, click on <Whirle> and choose the fixed point.

3. Stretch. You may choose either horizontal or vertical stretching: click on the corresponding double-arrows in the stretching field. To their right, there is a stretching factor of 2x to 35x. Notice that, on the torus, you needn't have larger factors since on the torus, 36=-35. Hence, you may first stretch by 35 and then reflect (in the same direction!) to get 36 as a stretching factor. After having chosen this factor, click on <Stretch> and choose the fixed point. The transformation is ready.

For sorcerers: Stretching once more shows the advantage of working with th prime number 71. Stretching twice by factor 12 means stretching by 12x12=144, and 144=2x71+2. This means that stretching by 12 is something like stretching by square root of 2!  This means that you can do seemingly impossible stretchings by the choice of the 71 torus.

4. Scissor. There are four types of scissoring: to the left, to the right, upwards, downwards, please click on the corresponding arrows in the <Scissor> field. After the choice of the direction of scissoring, set the fixed point as above.

Geometrically, the scissoring transformation to the right makes a script letter (inclination 45 degrees) out of a normal one. Thereby the horizontal line through the fixed point remains fixed.

The scissoring transformation to the left makes a counter-script letter (inclination 135 degrees) out of a normal one. Thereby the horizontal line through the fixed point remains fixed.

The downward scissoring transformation transforms a letter rota
ted by 90 degrees into a script rotated letter (vertical inclination 45 degrees). The vertical line through the fixed point remains fixed.

The upward scissoring transformation transforms a letter rotated by 90 degrees into a counter-script rotated letter (vertical inclination 135 degrees). The vertical line through the fixed point remains fixed.


4.4.3.4 Translation plus standard transform

The second strategy also uses standard transformations. But you start defining a translation and after this transformation, you make a standard transformation.

You start by defining the target point, where the centre of the 71x71 field has to be transformed. Click on this point. 
Then, you define a standard transformation having this target point as a fixed point. To do so, it is sufficient to define a standard transformation as was described in 4.4.3.3 and to click on the corresponding field (<Reflect>, <Whirle>, <Stretch>, <Scissor>).


4.4.3.5 General transformations

If you don't care about standard transformations, either because you want to do something very special, or because you want to do something very wild, then the third strategy is the right thing.

This strategy looks very simple. You just have to click on three arbitrary points of the quadratic 71x71 field and your transfor
mation is defined, we are going to explain, what you have done. You can see that the transformation is defined since a correspon
ding parallelogram defined by the three points as beeing three of its vertices appears on the field.

What is the meaning of the three points? The centre (36,36) is moved to the first point of your choice, like with the second strategy. The second point is (by definition!) the image of the horizontal unit (37,36). The third point is (by definition!) the image of the vertical unit (36,37). Since we restrict to transformations where straight lines are transformed into straight lines, this information already fixes the entire transformation.

The above parallelogram shows the transformation of the small square with edge length one and centre (36,36) as its left lower vertex.

Every transformation can be defined by a succession of three independent points of the 71x71 field. Every point is a choice out of 71x71=5041 possibilities. Hence, the triple choice is one out of 5041x5041x5041=128'100'283'921, roughly 128 billion trans
formations.


4.4.3.6 Inverse transformations

If you click on <inverse> when working with one of the three strategies, you don't choose the transformation but its inverse.

For example, the inverse of whiling 3 times is whirling 21 times since the combination of whirling 3x and 21x gives a whirle by 24, i.e. everything remains fixed. This means that whirling 21x has taken back the total effect of whirling 3x. This is the meaning of "inverse". Similarly, the inverse of a clockwise rotation of 90 degrees is the counter-clockwise rotation of 90 degrees or else the clockwise rotation by 270 degrees, with the same fixed point.

This inversion process always works within the first and the second strategy.

But for the third strategy this may fail. For example, if you set the third point onto the second point, there is no inverse: this would have to produce the impossible, to send one point to two different ones. In this case, a warning box appears and you have to choose a new transformation. It is the prime number 71 again which prevents you from getting in such a mess for a maximal number of situations.


4.4.3.7 The matrix of a transformation

Only for mathematically interested users! For every transforma
tion as defined by the above strategies, its matrix appears to the right. It is a 3x3 matrix of the affine transformation we are dealing with. Its coefficients refer to the centre (36,36) and to the standard base: horizontal and vertical unity. If you want to calculate the transformed coordinates of a point (x,y), write the row vector (1,x,y) and multiply it from the right with the given matrix. The product row vector will have coordinates (1,w,z) and the image of (x,y) is (w,z). Please do your calculations modulo 71!


4.4.3.8 Placing transformations

When you have defined a transformation, you may place it into a stock of eight possible transformations. To do so, press the mouse button on the pulldown box with default <Trans 1>. Then hold the button and move to the place (Trans 1 - Trans 8) where you want to place your transformation. Now, release the button, and the placement is done. The already existing transformation on this place will be erased; default is the unity transformation leaving everything fixed. If you don't want to place this transformation, just move out of the pulldown box with the pointer and then release the button. You may give the transforma
tions your own names, see 4.4.4.9.


4.4.3.9 Chains of transformations

When clicking on <Composition/Transformation chains>, a dialogue box opens where four combinations of chains of transformations can be defined. The candidates for such chains are the eight transformations within the stock defined by 4.4.3.8. These transformations can be renamed by obvious procedure (see orche
stration box 3.2) in this box, their names will appear in the pulldown box described in 4.4.3.8. You may also rename the four possible combinations. To the right of their names, these combinations may be defined by setting positive or negative numbers 1, -1, 2, -2, ..., 8, -8. For example: 342-13228-2-2. A positive number n means executing the nth transformation out of the given stock. A negative number -n means executing the inverse of the nth transformation of our stock (If this is possible!). The combination means that first, you execute the first transfor
mation from the left, then the second from the left etc. till the last (right) transformation is executed. The total effect is a new transformation which you have composed by use of some of the given stock. If you have set a negative number whose inverse transformation does not exist, a warning box will appear in case you try to choose the combination within the field <Composition/Transformation> (see 4.4.3.10).


4.4.3.10 Choice of transformations and transformation chains

You may choose one of the eight transformations of the actual stock or either one of the four combinations by click on the pulldown menu with default <Draft> which appears on both, <Composition/Local score> and <Composition/Transformation>, see also 4.4.3.1. The extra place named "Draft" always contains the transformation which you did define last. It will not be erased by a choice as described here.


4.4.4 Musical meaning of transformations

Together with the ornamental operations, transformations are the essence of structural thinking in music. They describe essential parts of what - on the rational level - has been used from the beginning with Pythagoras to the contrapuntal tradition and the Viennese classics up to the modern dodecaphonic technique and the serialists.

Every transformation on a determined parameter plane, and in particular a standard transformation, is musically reasonable. Hence, if you define a "wild" transformation by strategy three (4.4.3.5), it only is wild because it is a complicated chain of "tame", i.e. easily comprehensible transformations like retrograde and the like.

In the following, we discuss some musical processes appearing as transformations in presto.

Transposition: It is a vertical movement within the plane Onset/Pitch.

Repetition: It is - in particular in the shape of a "da capo" - a horizontal movement in onset direction. The other parameters are not affected. The moved material is united to the existing material (copy in onset time).

Inversion: It is a horizontal reflection in the plane Onset/Pitch (4.3.2.1). It is used in contrapuntal composition technique.

Retrograde: In the plane Onset/Duration, the retrograde is a vertical reflection (exchange of succession of onsets) followed by a scissoring to the left (4.3.2.3). It is also used for contraapuntal techniques.

Retrograde of inversion: It is a rotation of 180 degrees in the plane Onset/Pitch, followed by a scissoring to the left in the plane Onset/Duration. Its meaning is that of inversion and retro
grade.

Exchange of parameters: The exchange of two parameters is a reflection at the diagonal in the plane of these two parameters. It is a serial technique.

Arpeggio: It is a scissoring transformation to the right in the plane Onset/Pitch if you start from a chord. Its meaning is universal like that of transposition and repetition.

Augmentation: It means the the streching of distances of onsets in horizontal direction in the plane Onset/Duration. If stretching in vertical direction, too, you may also augment the durations. This is essentially done within the dilatation command (see 4.3.4).

Crescendo/Diminuendo: This is a vertical scissoring upwards/downwards in the plane Onset/Loudness when you start from a set of sounds of constant loudness.

In the following, we describe the musical meaning of further presto transformations which may be defined by the third strategy (4.4.2.5).

Equalizing of parameter values: In the plane Onset/Duration, you may equalize all sounds you wish to a fixed duration/loudness (You may also do this via colouring by hidden parameter values (4.4.2.4).):

-the centre moves vertically to the desired value;

-the horizontal unit moves vertically to the same value;

-the vertical unit moves vertically to the same point as the centre.

Formation of chords from non-simultaneous sounds: You are in the plane Onset/Pitch. You want to move a set of sounds to a fixed onset.

-Move the centre horizontally to the required onset;

-move the horizontal unit to the same point as the centre;

-move the vertical unit horizontally to the same onset as the centre.

Mixing up harmonics and rhythmics. If you leave fixed the centre, move the horizontal unit to (37,37) and the vertical unit to (35,37), the plane is turned by 45 degrees and dilated. Here, vertical structures (harmonics) get a horizontal component (rhythmical), and rhythmical elements get a harmonic projection.


5. RECORDING

5.1 Metronome

5.1.1 Beginning of validity range

If you click on <Instruments/Metronome>, everything which you define then, will refer to the actual position of the score slider as being the beginning of the new metronome.


5.1.2 Setting a metronome

A metronome consists of bar, tempo and resolution:

As a bar, you may choose a fraction like 3/4.

The tempo number behind M.M., e.g. 128, relates to the nominator of the bar (quarters in our example), the metre of this bar, and tells how many of this nominator units (128 quarters in our example) are played per minute.

The resolution, e.g. 3, means that every unit of the metre (a quarter in our example) is resolved or quantized in 3 equal fractions, twelfths in our example.

The presto-default of the metronome from onset 1 on is bar 4/4, M.M.=128, resolution=4, i.e. the tempo is 4x128=512 onsets per minute.

You may define these three data independently. The input works on the respective number fields. You confirm the definition of a metronome by a click on <Set>.

In that case, at the position of the score slider, a thick mark is set over the score for the beginning of a new metronome. Short, thin marks with distance equal to the resolution number and long, thin marks for the beginning of every new bar are following.

The tempo curve is constant at the M.M. level and the correspon
ding resolution level, together with a support point at the beginning of the first bar.

The next support point is set at the same level and one onset before the next existing support point. This prevents an existing tempo curve to be destroyed by this metronome setting.

If you want to set the new tempo without respecting the existing support points, then you have to clear the tempo by the function <Block/Flatten tempo> in order to eliminate the distur
bing/superfluous support points. If you want to preserve the existing tempo curve, clear the M.M. number by [Esc]: The M.M. will be accommodated to the existing curve. If you want no metronome within a certain sector, please set a new metronome with resolution 0.


5.1.3 Delete metronome

Except the default metronome at onset one, every metronome may be deleted. To do this, go to the onset of the beginning of the metronome and click on <Instruments/Metronome>. Then click on <Delete>. This implies that the preceding metronome will extend its validity range, but pay attention to support points preventing the preceding metronome to take its values.


5.1.4 Activating a metronome

By a click on <Listen metronome> and confirmation with click on <Ok> within the dialogue box of the metronome, the metronome will be audible/quiet when listening via <Play> or when recording (5.2) in the global score. In the local score, you may activate or desactivate the metronome directly with a click on <Instruments/Metronome>. An active metronome is indicated by a check.

If a metronome is active, a stock of metronome ticks is generated according to the tempo curve. In order not to loose too much time, this stock goes till the first gap of at least score length, where there are neither active icons nor active blocks. If you want to pla a long piece with the metronome, please set a corresponding block. But you may also proceed with playing after the metronome stopped ticking.


5.2 Setting the instrument

5.2.1 Presets for recording

If ou want to record by a MIDI instrument or by the mouse, you position the score slider at the beginning of your recording onset and set the metronome you wish.

Before recording, decide whether you want to hear the metronome and set the corresponding activity state.

Now click on <Instrumens/Recording> and you are in the dialogue fields for recording.


5.2.2 Recording dynamics

To the right of the fields ppp and fff, you may set the lower and upper bound of the dynamics of your instrument relative to the total dynamics (1-71). This setting is visible over the drawing board to the left (see 5.3.1.1) as a darkened beam.

This possibility is recommended if one does not completely control the dynamics of ones instrument.


5.2.3 Choice of the instrument icon and activating icons

You choose the instrument icon with which you want to record as well as the active icons with the method of the local score (4.4.1.1): the recording icon is inverted (state 3, see 2.6.4), the active ones are in state 2 (check). Here too, the new setting is confirmed when the pointer leaves the frame of the icon field.


5.3 Recording modes

5.3.1 MIDI instruments and mouse

5.3.1.1 Play and draw

You can record simultaneously with a MIDI instrument (for instance with the left hand) and with the mouse (with the right hand). Recording with the mouse is done on the quadratic local score field to the left of the recording display. You hold the left button pressed down and move. The parameter plane is that of Loudness/Pitch known from the local score. The duration of a sound is the real time duration of your holding down on a fixed point (and maximal 71 onsets). In contrast to the local score, the drawn points are not visualized since you would soon get a chaotic black surface without any meaning. It is like a graphic keyboard.

The activity of the metronome is set in <Instruments/Metronome>.


5.3.1.2 Choice of tonalities

In the dialogue field for tonalities, you may choose to record only sounds whose pitches stay within a determined tonality. You may define this restriction inedpendently for the keyboard or for the mouse. To set the restriction, click on the small squares to the left of <keyboard> resp. <mouse> (a cross appears for an active restriction). To choose the tonality, click on <tonality> and choose it as described in 4.3.3.7, confirm your choice by a click on <Ok>.


5.3.2 Playing the global score

If you click a cross to the left of <Play global score> you will hear the global score from the position of the score slider, of course only with respect to the active icons.


5.3.3 Recording

If you don't click a cross to the left of <Record>, your playing will not be recorded, it is only an exercise, independently of the setting of 5.3.2.

If you make a cross there, your play is recorded and may be cecked and worked out on the (global) score.

If you have decided that your record should be erased, click on <Reject>, and your part is deleted. But the rest remains as it was, of course. If you want to save your part, click on <Take over> and your part is united with the rest.

Pay attention: You may modify the record on the global score at will and before the decision Reject/Take over. You may after all decide to reject - there is no problem. But don't forget to click on <Take over> if you like the result. If you forget this, you may loose the result much later when you reject another recorded part (see also 5.3.4)!


5.3.4 Starting and Stopping a record

If you are ready for recording within one of the four modes described in 5.3.2 and 5.3.3, click on <Start>. If you have made records before without deciding to take over or not, there will be a dialogue box asking you whether you want to take over the preceeding. After your answer, the MIDI events of the existing parts are created and you may start as soon as the corresponding dialogue box asks you to do so.

The end of this recording session is indicated by a click on <Stop>.

The role of MIDI messages in presto is described in chapter 6.


MIDI is an acronym for Musical Instrument Digital Interface and means an industrial standard of digital information transfer of musical data between computers, synthesizers, samplers, effect machines etc., which we shall call MIDI devices in what follows. MIDI was introduced 1983.

MIDI has two components: Hard- and software. The first regulates the transfer of electric signals, the second defines their shape as information carrier.


6.1 MIDI hardware

To connect MIDI devices, there are standardized MIDI cables with 5-pin DIN connectors. It is irrelevant in which direction you connect MIDI cables to your devices.

The electric signals flow from the MIDI-OUT or MIDI-THRU port to the MIDI-IN port. Other connections are nonsense, but it will not damage you devices. The MIDI-THRU port serves for taking over data directly form the MIDI-IN port without change in order to transmit them to another device. Data coming from a MIDI-OUT port may be sent simultaneously to several MIDI-IN ports. But one MIDI-IN port can only receive data from one other port.


6.2 MIDI Software

The digital signal transfer is serial: The information is transmitted as a sequence of bits, the information units. The bit is the possibility of choosing between two states: "ON" and "OFF", in numbers: 0 and 1. Hence, the information sequence consists of zeroes and ones. The rate of transfer is 31'250 bits per second (=Bauds).

The specific character of MIDI is the codex which transforms sequences of bits into messages for MIDI devices. In principle, this codex is arbitrary but, fortunately, an international standard was established in 1983. Minor deviations of particular manufacturers are inevitable since every language has its dialects. But the most important messages are codified in a unequivocal way.

The MIDI codex is essentially musical since its messages don't touch acoustical data of sounds but score-related informations - with the difference that they are more precise than classical notation. The receiver of MIDI messages is a device which is able to produce different kinds of sounds. It plays the role of an universal orchestra whose members have no technical problems in interpreting any score as soon as they are told in a precise way what to play (onset, duration, loudness, pitch, instrumental colour etc.). The technical problems only arise if too many messages are produced per second or if zu many devices are serially coupled.


6.3 The MIDI Messages and their Role with presto

MIDI messages are grouped to several subsets. We are going to sketch their meaning when working with presto.


6.3.1 Channel Messages

6.3.1.1 Channel Number

Channel means MIDI-channel, one of sixteen possible adresses numbered by 1-16 (or 00-15) in order to distinguish specific settings of sounds of MIDI-devices. With presto, you can assign a channel number to each icon (3.1).

Channel messages are messages specified by a channel number. They ared devided into two subsets: Channel voice messages describe parameters defining the shape of single voices, whereas channel mode messages describe different modes of behaviour of the MIDI device when receiving channel voice messages.


6.3.2 Channel Voice Messages

6.3.2.1 Note ON/Note OFF

The message Note ON relates to the physical onset, the message Note OPP to the time, when the sound ends after its duration. For certain sounds, the sound may fade aqway after the Note OFF like with natural instruments.

These two physical time informations are codified through the musical parameters of onset and duration and the tempo curve.

6.3.2.2 Key

The key number (0-127) is an abstract number associated with keys of a keyboard. Normally, it means the pitch steps in halftones for the wide-spread well-tempered tuning.

For certain synthesizers, you may also define other tunings (just, pythagorean, mocrotonal etc.), and the key number will refer to those steps. With drum computers, the key numbers may codify different drum sounds or else the pitch shift of a single drum sound (usually a sample) is programmed. But then, you will notice that only a minor deviation from the original sample will sound reasonably.

In 2.1.2, we discussed the connection between the 71 pitches of presto and the key numbers.


6.3.2.3 Velocity ON/Velocity OFF

The "velocity ON" message is a number between 0 and 127 and means the velocity with which a key is struck, i.e. the loudness of a sound. Most of the MIDI devices as well as presto are not sensible to "Velocity OFF", a number between 0 and 127 meaning the velocity of release of a key. In musicology, this information would be associated to sound colour rather than to loudness.

6.3.2.4 Program Change

This message is a number between 0 and 127 and defines a specific sound of the MIDI device within a defined channel. Please consult the manual of your MIDI device to look up the corresponence of sounds and program numbers, a general standard still is not universally applicable.

6.3.2.5 Control Change Messages

This kind of message, also defined by a number from 0 to 127, relates to a variety of so-called controllers like pitch bend, after touch, modulation wheel, breath control etc. in order to control expressive aspects of sound not described by the classical geometric parameters (6.3.2.1-6.3.2.3). Controllers heavily depend upon the state of the technology. Presently, presto ignores these messages since they may become absurd when  transformations are applied.
 6.3.3 Channel Mode Messages

There are two tyes of variables within the classical setting of these messages, each may take two values:

- Omni ON/OFF: With "Omni ON", the channel information of channel voice messages is ignored resp. it receives messages from all channels. With "Omni OFF", channel informations are taken into account.

- Poly/Mono: For the poly-mode, the MIDI device receives polyphonic messages, e.g. chords are realized as they are defined. For the momo-mode, only a monophonic selection of a polyphonic material is realized per channel, the total material being distributed among different channels.

The four resulting combined modes are ON/Poly, ON/Mono, OFF/Poly, OFF/Mono; recently, a fifth mode called Multi has been successfully introduced beyound the classical MIDI-specification of 1983. It allows for polyphonic sounds on several channels. Please set your MIDI device to the desired mode.

6.3.4 Further Types of Messages

There are still more types of MIDI messages, like system exclusive messages, system common messages, real time messages and the like. They are partly related to special types of MIDI devices, partly are they used to handle postproduction. If you want to use them, please save a presto composition as MIDI file (4.1.7) and work on the additional messages on a specialized program, where the MIDI file may be loaded.

Troubleshooting

The monitor stays dark
Check whether the monitor is connected to the computer and that it is switched on. Make sure that the presto key is not inserted the wrong way (correct: the Beethoven image must look upwards).
You can't hear anything
Check the MIDI cables of your devices. Are the MIDI connectors correctly inserted? Is the configuration of your devices correct? Check your audio periphery, too!
presto breaks down
Turn off your Atari for ten seconds and try again. Maybe something was hidden in your system which was disturbing presto.
Clean the contacts of the key with alcohol and clean cloth.
Maybe, there are some resident programs or accessories of bad programming quality and therefore incompatible with presto. Remove these resident programs and accessories and try again. Boot your Atari with the presto disk.
Finally, it may be that presto isn't compatible with internal or external hardware which doesn't fit with the norms of Atari. Remove this kind of hardware.



 


 

  
 


     













 
   
 


     








 









  




  








  
