Changing the key signature of MIDI files

Key transpositions of MIDI files are relatively easy. The note value is the second byte of a NoteOn or NoteOff message:

&h90+ChanNo Note Velocity &h80+ChanNo Note Velocity

The quantity Note takes integer values from &h00 (0) to &h7F (127) following the chromatic scale. Middle C corresponds to Note = &h3C (60). Therefore, a transposition of […]