Re: Issue 1648 in lilypond: MIDI: no defined order between a simultaneous note-on and note-off

[lilypond]

Comment #4 on issue 1648 by address@hidden: MIDI: no defined order  
between a simultaneous note-on and note-off
http://code.google.com/p/lilypond/issues/detail?id=1648

> Is what the Windows Media Player does the preferred/expected behaviour?

It is the simple behavior, and expected (google "MIDI overlapping unisons").
It is not preferred for LilyPond 2.13.61 because we sometimes fail to hear  
some notes we typed into Lilypond input.  It is not preferred by Timidity++  
developers either, because their option --overlap-voice gives more  
sophisticated behavior and is set by default.

In the past, the class Midi_walker caught and merged overlapping unisons  
before output to the MIDI file.  (This is the function that is being  
improved in response
to issue 1647, with much the same effect as timidity's --overlap-voice.)

Recent changes to the MIDI data flow prevent Midi_walker from doing this  
job.

Long term, I hope to align concepts (MIDIchannel, MIDItrack, Voice) with  
the classes in the implementation (Midi_event, Midi_stream, Midi_walker,  
Midi_chunk, Midi_track, Midi_channel_item, Audio_column, Audio_staff,  
Staff_performer) and the maps that link them (staff_map channel_map  
static_channel_map) so that the code can access the data it should be  
working on.

Short term, the patch in comment 2 makes the recent changes to MIDI data  
flow be an option rather than default.