Abbreviation for General MIDI 2, an extended General MIDI standard. GM2 was introduced in 1999 to raise the quality and provide even more standardization and control over the creation and playback of General MIDI files. GM2 is of course similar to General MIDI. The major changes are as follows: GM2 compliant sound modules or keyboards must be 32 voice (as opposed to 24), have 256 patches or programs (as opposed to 128), and have many more defined continuous controllers (specific controller definitions can be found at the MIDIMA site). A GM2 device is fully backward compatible with older GM files.