These messages are specific to a certain device. Although not part of the audio device driver's architecture, they are included here. Notice in the following example that the 6th MIDI byte identifies the specific IBM device that is addressed:
M-ACPA (IBM Audio Capture & Playback Adapter)
Program Change Enable
This message instructs the M-ACPA synthesizer to honor or ignore MIDI program change messages (Cn).
F0 00 00 3A 02 01 01 ee 00 F7 ee = Program Changes Enable (0 = disabled, 1 = enabled; default)
By default, program changes are honored. Notice that this message does not affect generic sound selection messages, which are always honored.