A universal System Exclusive command that activates General MIDI mode on a GM instrument. It allows the device to respond correctly to General MIDI program change messages (0-127). The same command also sets all controllers to their default values and switches off any notes that might be playing by means of an All Notes Off message.
You can easily insert a GM Reset message into your sequenced song by activating your sequencer’s System Exclusive recorder (different programs have different SysEx features) and inserting the hexadecimal string:
F0 7E 7F 09 01 F7