MOTM

In a message dated 12/30/2000 9:40:15 AM, hugo.haesaert@... writes:

>Check out :
>
>http://www.windworld.com/emi/
>
>Experimental Musical Instruments homepage .

Hi Hugo,

Great to hear from you again! This is absolutely perfect -- they even sell 
those oddball PUs I was thinking about! I should say "great minds think 
alike" -- not mine, however. Mr. "Beetlebaum" had suggested I look at the 
Bart Hopkin book "Musical Instrument Design." Hopkin was the guy behind EMI 
Quarterly and the EMI website. I actually had a copy of this book on my 
bookshelf (I got it from Paul recently in one of his auctions). I've spent a 
brief time looking at it since yesterday, and can highly recommend it for 
anyone with even a passing interest in these types of issues. It even has a 
short chapter devoted to resonators and radiators, as well as a short 
appendix devoted to amplification using different types of PUs.

Anyway, in the chapter "Chordophones" there is a section on Electromagnetism 
as a way to get strings vibrating. Specifically: 

"You can reverse the process [of using a PU to generate an AC electrical 
current from a moving string] by sending a heavily amplified alternating 
current pattern to a pickup, speaker driver, or other device which will serve 
as an electromagnet. When the electromagnet is held close to a steel string, 
it will drive the string. If the frequency of the signal sent to the 
electromagnet doesn't approximate any of the string's natural frequencies, 
the string doesn't respond much, but if there is a match, the string shows a 
generous resonance response, with gradually increasing amplitude." 

It goes on to mention that using this technique for each string of the piano 
was how Stephen Scott and Alex Stahl did their "bowed piano" recordings in 
the 80s (I really liked these, BTW). Hopkin also says: 

"Another [way] is to use a pickup in the conventional manner to pick up a 
string's frequency, and send it to an amplifier, and then back to another 
electromagnet held near the string, to perpetuate the sound. This is the idea 
behind the electric guitarist's sustain-enhancing device called the E--Bow."

Sorry for the length of this thread to those not interested in these ideas, 
but I can tell at least a few people are as interested as I am (if not more 
so).
JB

Hi JB n All !

See, no ot sign anymore ;^P

It's widely accepted that concepts of analogue synthesis are ON Topic 
for this list .

May i remind you that many of these describe and/or mimic processes 
analogous to the physical world .

Resonating bodies are fundamental to these processes .

OT ?

Hmm .

Oh yes, i was just listening to 

Orbitones Spoon Harps & Bellowphones
experimental musical instruments
Book & Compact Disc Written and Produced by
Bart Hopkin
Foreword by
Robert Moog

And a very good and interesting listen it truly is .

Closes the circle beautifully .  Nuff said ?

A happy millennium everyone,

and may your oscillations reach
ever-increasing numbers of people
and resonating bodies
in ever-expanding,
distant galaxies

%^P

Keep 'em oscillating :-)

Hugo
=