Overview

The MMA's GM Developer Guidelines document (also included in the Complete MIDI 1.0Specification) describes additional recommendations and clarifications of the GM Specification for content producers and device makers, to insure improved compatibility among GM products.

List of New Recommendations
Data Entry Controllers (CC#6, CC#38)
RNP/NRPN Null Function (C/A JMSC-0011)
Mutually Exclusive use of Hi-hat and Triangle in Percussion Channel
Response to Note-Off for Long Whistle and Long Guiro in Percussion Channel
Response to All Sounds Off Message (cc120)

List of Topics Clarified
Defined response to Turn GM System On Message
Defined response to Reset All Controllers Message
Defined Channel Priority scheme for Voice Allocation
Defined Volume and Expression Controller response curves
Defined Response to PAN Controller Messages
Defined Response for Non-GM Controllers (Bank Select, Effects, etc.)
Defined Response for Aftertouch (MIDI 1.0 Detailed Specification Recommendation)

List of Topics Discussed
Response to "GM System On" Message
Response to "Reset All Controllers" Message
RPN/NRPN Null Function Value
Use of Data Entry Controllers
GM Polyphony Requirements
GM Voice Allocation - Overflow and Channel Priority
Volume Expression & Master Volume Response
Response to Pan Use of Bank Select Messages
Response to Program Changes
Built-In Effects & Response to Effects Controllers
Aftertouch
Additional Notes About Controllers
Additional Instrument Sounds (Extensions to GM)
Additional Drum Sounds & Kits (Extensions to GM)
Response to Note-off on Channel 10 (Percussion)
Mutually-Exclusive Percussion
File Formats and Editing Capability
MIDI Player Control: Starting in the Middle
File Data: Prep bars
File Data: Pickup bars
File Data: SMF Marker Event
File Data: Other Meta-Events
File Data: Channel Assignments
File Data: Multiple Devices (non-GM)