Official MIDI Specifications

General MIDI

GMLOGO
The General MIDI Specifications (GM 1, GM 2, and GM Lite) define specific features and behaviors for compliant MIDI devices. In particular, files created for GM devices all use the same GM Sound Set which helps provide for more consistant playback among different MIDI devices.

Note: The GM 1 specification was superceded in 1999 by General MIDI 2 which added support for additional features and capabilities which had become commonly available since GM 1 devices first appeared. However, GM 1 remains a popular format and is still commonly used for music distributed in Standard MIDI File (*.mid) format.
This Specification outlines a minimum MIDI configuration of a “General MIDI System” which defines a certain class of MIDI controlled sound generators. The General MIDI (or GM) System provides a high degree of compatibility between MIDI synthesizers, and adds the ability to play songs (in the form of MIDI data) created for any given MIDI synthesizer module that follows this Specification.

This class of products are intended for broad applications in the music, consumer, and entertainment markets, due to increased compatibility and unprecedented ease-of-use.
General MIDI 2 is a group of extensions made to General MIDI (Level 1) allowing for expanded standardized control of MIDI devices. This increased functionality includes extended sounds sets and additional performance and control parameters.
The General MIDI Lite specification was developed to meet a particular market requirement. The specification defines three things:
  • A set of features for fixed-polyphony GM Lite devices
  • Authoring guidelines for music data in SMF (Standard MIDI File) format that is intended for playback on GM Lite devices
  • Implementation guidelines for GM Lite file players 
Note: There is also a Scalable Polyphony MIDI (SP-MIDI) Specification which compliments GML by defining features and authoring guidelines for flexible-polyphony MIDI devices and content.