Official MIDI Specifications

General MIDI Level 1

GM 1 Features (Required)

To be GM 1 compatible, a GM 1 sound generating device (keyboard, sound module, sound card, IC, software program or other product) must meet the General MIDI System Level 1 performance requirements outlined below, instantaneously upon demand, and without additional modification or adjustment/configuration by the user.
  • Voices: A minimum of either 24 fully dynamically allocated voices are available simultaneously for both melodic and percussive sounds, or 16 dynamically allocated voices are available for melody plus 8 for percussion. All voices respond to velocity.

  • Channels: All 16 MIDI Channels are supported. Each Channel can play a variable number of voices (polyphony). Each Channel can play a different instrument (sound/patch/timbre). Key-based percussion is always on MIDI Channel 10.

  • Instruments: A minimum of 16 simultaneous and different timbres playing various instruments. A minimum of 128 preset instruments (MIDI program numbers) conforming to the GM 1 Instrument Patch Map, and 47 percussion sounds which conform to the GM 1 Percussion Key Map.

  • Channel Messages: Support for continuous controllers 1, 7, 10, 11, 64, 121 and 123; RPN #s 0, 1, 2; Channel Pressure, Pitch Bend.

  • Other Messages: Respond to the data entry controller and the RPNs for fine and coarse tuning and pitch bend range, as well as all General MIDI Level 1 System Messages.