When I wrote my previous reply, I was curious as to how you were listening to the piece following your edits. Possibilities would have includee:
--playback from internal memory of the Mark IV PRO or from a USB flash drive
--playback on the Mark IV PRO, receiving data from the computer, in which case the Disklavier is set to receive MIDI data in either real time or with a 500ms delay added
--playback using the tone generator of your computer or a soft synth running on your computer
--playback using another MIDI device
Unless you are playing back on the Mark IV PRO from its internal memory or from a USB flash drive, your perception of the quality of the playback may have been affected by any of several factors. I'll assume playback from internal memory or from USB flash drive.
All Disklaviers record performances as MIDI data. The PRO, however, uses normally unused MIDI controllers along with polyphonic aftertouch messages to store extra bits of resolution. This means that note-on and note-off messages are effectively recorded on a scale of 0-1023 instead of the usual MIDI scale of 0-127 and the left and right pedals are recorded on a scale of 0-255 instead of 0-127. In addition to recording hammer velocity (as note-on messages), the PRO also records key down velocity.
In theory, you should be able to edit a PRO recording in a MIDI sequencer and not lose any of the granularity of the recorded data. However, typical MIDI sequencers are not pure MIDI editors: most of them import MIDI data into their own format and then export to MIDI when you are done. During the import and/or export process, they typically mess with the order of the extra MIDI events that you find in a PRO file. These extra MIDI events, which occur on the same clock tick, must be in a particular order so that the Disklavier can interpret them correctly.
It is entirely possibly that when you edited and saved your file, you effectively lost the granularity of the data. However, the overall range of expression (from the softest to the loudest notes) should be unchanged. Your PRO has an amazing set of solenoids and an advanced servo mechanism, which means that it should do a really great job playing data with normal MIDI resolution.
Regrettably, there are no good choices for a program that can edit the MIDI data in a PRO recording.
For more information about how the PRO works, you might want to check out the video that I made and posted on the home page of the Disklavier Education Network:
Regards,
PianoBench
On Sep 2, 2014, at 6:52 AM, Robert Hall eviscent@... [disklavier] <disklavier@yahoogroups.com> wrote:
After I edited there seemed to be less discrepancy, the performance seemed more crude. I had read the promo about the Pro technology which is summarized here: (lifted from Wikipedia)
In 1999, "Disklavier Pro" was introduced to the American market, the "II Pro". A key selling feature of this version was a claim of greater playback accuracy than had been possible with previously available models.[3] The Pro made use of a proprietary enhancement of MIDI data, which subdivided the timing information in an effort to allow greater precision. Rather than using the standard 127 levels of midi velocity, Yamaha introduced 1023 levels for KeyAfterTouch, NoteOn and NoteOff. A similar principle was applied to the pedal performance data, using 256 increments of measurement in an effort to allow finer capture and reproduction of, for example, half and quarter pedaling by the player. These developments allowed Yamaha to claim a greater overall accuracy in the reproduction of an original piano performance.[3]I assumed that perhaps in editing in the Midi format I had lost something.Bob