As a follow-up to Rick Cooley's comments in MMD 960309 regarding timing
differences between Channel 1 and the other channels for the Disklavier,
I add the following.

If you attempt to transmit a multi-channel MIDI file from an external
source to a Disklavier and other MIDI devices (sound module, second
instrument, etc.) all of the MIDI information must pass *first* through
the Disklavier and then to the other devices. This is because the
Disklavier is supposed to introduce a delay of exactly 500 milliseconds
(1/2 second to us humans) in the MIDI signals it forwards to the other
devices. The delay is introduced because the Disklavier takes 500 milli-
seconds to produce the notes it receives on the MIDI channel it is
assigned to play from. The result is synchronized music from multiple
instruments.

It turns out there is a way for the user* to fine-tune the transmission
delay for the secondary instruments, and this may be another means of
addressing the problem that Rick has encountered. I have not tried it for
music played *from* the Disklavier, but since the delay for transmitting
to the other MIDI devices is the parameter being adjusted, I believe that
modifying it influences the MIDI OUT port timing, whether the data source
is the Disklaviers floppy or the MIDI IN port.

Bob Fitterman¶
bobf@ilx.com

* I guess the pneumatic guys would refer to the user as the pianolist,
but I think it wouldn't befit the the technology to use that term here.

 [ As used by Douglas Henderson and Dan Wilson, "pianolist" is one who
 [ controls the performance of the music as it is playing, by manually
 [ altering the tempo and volume and operating controls such as the
 [ pedals.  In most cases the Midi instruments are more like a repro-
 [ ducing piano performance, which has no means of real-time alteration
 [ other than the tempo.  -- Robbie