Re: Map voices to channels in MIDI output

[Keith OHara]

Jan,
 Commits e5380f2 and 8dc343b break the MIDI output from all the examples in the 
documentation that use midiInstrument, and the regtest 
‘midi-volume-equaliser.ly’.  The midi output is much less useful for 
proofreading, because all the voices sound the same.

The problem is that the all settings at Staff context go out on the same midi 
channel 0.  It does not matter that they are in different 'tracks' because 
tracks are merely for file organization; track information does not go down the 
cable.  Now, it is possible to route different tracks to different MIDI ports 
(corresponding to separate cables) but LilyPond does not do this routing, and I 
don't think many software midi players support multiple ports anyway.

Do you need to see bug reports on the tracker ?
or can we revert these two commits until your change is complete ?

Actually, I think the existing LilyPond solution, of moving the midi performer 
to Voice context, can do what your sponsor needs.  I'll try it and comment on 
the tracker issue 1548.
--
Keith