How the gizmo works - 3

• All of the ‘Hammond’ SoundFonts that the gizmo uses have only one patch in them.
• So ‘Program Change’ on the channels which have Hammond sounds will not do anything useful – there’s only one patch in the relevant bank.
• But, several of the channels use patches from the bank that contains the standard ‘General MIDI’ SoundFont.
• There are 128 patches in the ‘General MIDI’ SoundFont, and so for most channels that use this bank ( channels 8,9, and 11 – 16 in the default configuration ), ‘Program Change’ will select a different patch.
• MIDI channel 10 is special. It is the Percussion channel, and Program Change will not work on channel 10.
• General MIDI is a standard set of patch names – the full list of names can be found here :

https://www.midi.org/specifications/item/gm-level-1-sound-set