Greetings,  I am not sure of the exact needs of a PianoDisc user
in terms of changing channels of MIDI events.  I wrote a utility
that does several things to MIDI files including scaling of velocity,
and changing channel for parts that contain a MIDI patch within
a particular range.

For example, you can have the program change any event assigned to
a channel with a patch lower than 7 (the usual piano and piano-like
parts) to channel 1.  As I recall, the program leaves channel 2 events
on channel 2 (in order to keep left and right hands on separate
channels) but a subsequent processing with another option selected
will move all channel 2 events to channel 1.

Another option moves the pedal data to channel 3 for some Disklaviers
that work better that way.  The program works on whole folders (or
single files) so you can walk away while the processing is in progress.
The program can be instructed to leave the original files and create
new ones or to overwrite the original files.  Each subsequent
processing operation works only on the new files if this option is
selected.

If there is another need for PianoDisc users that the program does not
address, I can probably add that capability.  I could also make a stand
alone program to perform a specific task.  I have routines written (and
mostly debugged) to do just about anything to a MIDI file.  The program
has a lot of options stuffed into a rather dense interface.  There is
a help file that makes sense after a few readings.

You can find the program in two versions on my web site.  The "test"
version has a few more options and maybe fewer or maybe more bugs.
Comments, bug reports or suggestions for added features are welcome.
I plan to add more features for e-roll modification in the near future
or may make a separate program.

  http://www.spencerserolls.com/MidiMod/MidiMod2.zip
  http://www.spencerserolls.com/MidiMod/MidiMod2test.zip

Be sure to check out the rest of the site at the following link:
  http://www.spencerserolls.com

Best regards,
Spencer Chase
Laytonville, Calif.
http://www.spencerserolls.com/