diff -ur lilypond-2.13.0.orig/lily/midi-item.cc lilypond-2.13.0/lily/midi-item.cc
--- lilypond-2.13.0.orig/lily/midi-item.cc	2009-04-05 21:11:25.000000000 +0200
+++ lilypond-2.13.0/lily/midi-item.cc	2009-04-06 09:24:09.000000000 +0200
@@ -169,7 +169,8 @@
 Midi_note::Midi_note (Audio_note *a)
 {
   audio_ = a;
-  dynamic_byte_ = 0x7f;
+  dynamic_byte_ = 0x5a; 
+  // dynamic_byte_ = 0x7f;
 }
 
 
@@ -229,13 +230,14 @@
   //  0 should definitely be avoided, notes stick on some sound cards.
   // 64 is supposed to be neutral
 
-  aftertouch_byte_ = 64;
+  // proposed patch: use note_on with velocity=0 instead of note_off
+  aftertouch_byte_ = 0;
 }
 
 string
 Midi_note_off::to_string () const
 {
-  Byte status_byte = (char) (0x80 + channel_);
+  Byte status_byte = (char) (0x90 + channel_); //use note_on velocity=0
 
   string str = ::to_string ((char)status_byte);
   str += ::to_string ((char) (get_semitone_pitch () + Midi_note::c0_pitch_));