General MIDI 2 compatible synthesizers access all of the 256 instruments by setting cc#0 (Bank Select MSB) to 121 and using cc#32 (Bank Select LSB) to select the variation bank before a Program Change.
Variation bank 0 contains the full GM — that is, General MIDI 1 — sound set.
Variations using other bank numbers are new to General MIDI 2, and correspond to variation sounds introduced in Roland GS and Yamaha XG.
These are the same patch numbers as defined in the original version of GS.
Drum bank is accessed by setting cc#0 (Bank Select MSB) to 120 and cc#32 (Bank Select LSB) to 0 and PC (Program Change) to select drum kit.