General Midi (GM)

GM1, GM2, and GM Lite

In September of 1991 the MIDI Manufacturers Association (MMA) and the Japan MIDI Standards Committee (JMSC) created the "General MIDI Level 1" spec.  It was designed to provide a minimum level of performance compatibility among MIDI instruments.  Still, many manufacturers felt there needed to be additional functionality. In 1999, General MIDI 2 was released, which included a group of extensions to GM1.   All GM2 devices are backward compatible with GM1 !!

The General MIDI Lite device specification was released in 2001, and is intended for equipment that does not have the capability to support the full feature set defined in General MIDI 1.

 

General Midi 1

 

GM (General Midi) is a set of 128 Midi instruments, including drums.  It is the most widely used Midi set, and is used by virtually all of the synthesized midi codecs.  Most sound cards now come with a wavetable, but the table is based on the GM1, 128-instrument patch map.

 

Before the advent of General Midi  -  the old MIDI files created for use with one instrument could sound utterly different when played back on another system !!  In order to overcome this problem, General MIDI or GM was introduced in 1991. On any GM instrument, for instance, patch number 13 will be "marimba", though different GM instruments may have different ways of synthesizing the sound of the marimba.

 

NOTE:  instruments are also called "voices" or "presets"

 

General MIDI Level 1 Sound Set

General MIDI's most recognized feature is the defined list of sounds or "patches". However, General MIDI does not actually define the way the sound will be reproduced, only the name of that sound.

Though this can obviously result in wide variations in performance from the same song data on different GM sound sources, the authors of General MIDI felt it important to allow each manufacturer to have their own ideas and express their personal aesthetics when it comes to picking the exact timbres for each sound.

Each manufacturer must insure that their sounds provide an acceptable representation of song data written for General MIDI. Guidelines for developing GM compatible sound sets and song data are available through the MMA.

General MIDI Level 1 Instrument Patch Map

GM1 Instrument Families

The General MIDI Level 1 instrument sounds are grouped by families. In each family are 8 specific instruments.


PC#     Family                  PC#     Family

1-8     Piano                   65-72   Reed

9-16    Chromatic Percussion    73-80   Pipe

17-24   Organ                   81-88   Synth Lead

25-32   Guitar                  89-96   Synth Pad

33-40   Bass                    97-104  Synth Effects

41-48   Strings                 105-112 Ethnic

49-56   Ensemble                113-120 Percussive

57-64   Brass                   121-128 Sound Effects

GM1 Instrument Patch Map

Note: While GM1 does not define the actual characteristics of any sounds, the names in parentheses after each of the synth leads, pads, and sound effects are, in particular, intended only as guides).


PC#         Instrument

1.      Acoustic Grand Piano            65.     Soprano Sax

2.      Bright Acoustic Piano           66.     Alto Sax

3.      Electric Grand Piano            67.     Tenor Sax

4.      Honky-tonk Piano                68.     Baritone Sax

5.      Electric Piano 1                69.     Oboe

6.      Electric Piano 2                70.     English Horn

7.      Harpsichord                     71.     Bassoon

8.      Clavi                           72.     Clarinet

9.      Celesta                         73.     Piccolo

10.     Glockenspiel                    74.     Flute

11.     Music Box                       75.     Recorder

12.     Vibraphone                      76.     Pan Flute

13.     Marimba                         77.     Blown Bottle

14.     Xylophone                       78.     Shakuhachi

15.     Tubular Bells                   79.     Whistle

16.     Dulcimer                        80.     Ocarina

17.     Drawbar Organ                   81.     Lead 1 (square)

18.     Percussive Organ                82.     Lead 2 (sawtooth)

19.     Rock Organ                      83.     Lead 3 (calliope)

20.     Church Organ                    84.     Lead 4 (chiff)

21.     Reed Organ                      85.     Lead 5 (charang)

22.     Accordion                       86.     Lead 6 (voice)

23.     Harmonica                       87.     Lead 7 (fifths)

24.     Tango Accordion                 88.     Lead 8 (bass + lead)

25.     Acoustic Guitar (nylon)         89.     Pad 1 (new age)

26.     Acoustic Guitar (steel)         90.     Pad 2 (warm)

27.     Electric Guitar (jazz)          91.     Pad 3 (polysynth)

28.     Electric Guitar (clean)         92.     Pad 4 (choir)

29.     Electric Guitar (muted)         93.     Pad 5 (bowed)

30.     Overdriven Guitar               94.     Pad 6 (metallic)

31.     Distortion Guitar               95.     Pad 7 (halo)

32.     Guitar harmonics                96.     Pad 8 (sweep)

33.     Acoustic Bass                   97.     FX 1 (rain)

34.     Electric Bass (finger)          98.     FX 2 (soundtrack)

35.     Electric Bass (pick)            99.     FX 3 (crystal)

36.     Fretless Bass                   100.    FX 4 (atmosphere)

37.     Slap Bass 1                     101.    FX 5 (brightness)

38.     Slap Bass 2                     102.    FX 6 (goblins)

39.     Synth Bass 1                    103.    FX 7 (echoes)

40.     Synth Bass 2                    104.    FX 8 (sci-fi)

41.     Violin                          105.    Sitar

42.     Viola                           106.    Banjo

43.     Cello                           107.    Shamisen

44.     Contrabass                      108.    Koto

45.     Tremolo Strings                 109.    Kalimba

46.     Pizzicato Strings               110.    Bag pipe

47.     Orchestral Harp                 111.    Fiddle

48.     Timpani                         112.    Shanai

49.     String Ensemble 1               113.    Tinkle Bell

50.     String Ensemble 2               114.    Agogo

51.     SynthStrings 1                  115.    Steel Drums

52.     SynthStrings 2                  116.    Woodblock

53.     Choir Aahs                      117.    Taiko Drum

54.     Voice Oohs                      118.    Melodic Tom

55.     Synth Voice                     119.    Synth Drum

56.     Orchestra Hit                   120.    Reverse Cymbal

57.     Trumpet                         121.    Guitar Fret Noise

58.     Trombone                        122.    Breath Noise

59.     Tuba                            123.    Seashore

60.     Muted Trumpet                   124.    Bird Tweet

61.     French Horn                     125.    Telephone Ring

62.     Brass Section                   126.    Helicopter

63.     SynthBrass 1                    127.    Applause

64.     SynthBrass 2                    128.    Gunshot



General MIDI Level 1 Percussion Key Map

On MIDI Channel 10, each MIDI Note number ("Key#") corresponds to a different drum sound, as shown below. GM-compatible instruments must have the sounds on the keys shown here. While many current instruments also have additional sounds above or below the range show here, and may even have additional "kits" with variations of these sounds, only these sounds are supported by General MIDI Level 1 devices.

Key# Drum Sound      Key#    Drum Sound

35  Acoustic Bass Drum  59  Ride Cymbal 2

36  Bass Drum 1     60  Hi Bongo

37  Side Stick      61  Low Bongo

38  Acoustic Snare      62  Mute Hi Conga

39  Hand Clap       63  Open Hi Conga

40  Electric Snare      64  Low Conga

41  Low Floor Tom       65  High Timbale

42  Closed Hi Hat       66  Low Timbale

43  High Floor Tom      67  High Agogo

44  Pedal Hi-Hat        68  Low Agogo

45  Low Tom         69  Cabasa

46  Open Hi-Hat     70  Maracas

47  Low-Mid Tom         71  Short Whistle

48  Hi Mid Tom      72  Long Whistle

49  Crash Cymbal 1      73  Short Guiro

50  High Tom        74  Long Guiro

51  Ride Cymbal 1       75  Claves

52  Chinese Cymbal      76  Hi Wood Block

53  Ride Bell       77  Low Wood Block

54  Tambourine      78  Mute Cuica

55  Splash Cymbal       79  Open Cuica

56  Cowbell         80  Mute Triangle

57  Crash Cymbal 2      81  Open Triangle

58  Vibraslap       

 

General Midi 2

 

General MIDI 2 Specification

General MIDI 1 made great strides in the music industry by providing a platform for compatibility between device manufacturers and content providers. Still, many manufacturers felt there needed to be additional functionality. General MIDI 2 is a group of extensions made to General MIDI 1, which increases both the number of available sounds and the amount of control available for sound editing and musical performance. All GM2 devices are also fully compatible with General MIDI 1. 

To support these new GM2 features, the MIDI specification has been extended with numerous new messages. Portions of the MIDI Specification which have been enhanced include MIDI Tuning, Controllers, RPNs, and Universal System Exclusive Messages. Of particular significance are the new Universal System Exclusive Messages, including Controller Destination Setting, Key-Based Instrument Controllers, Global Parameter Control, and Master Fine/Coarse Tuning.

Summary of GM2 Requirements

GENERAL REQUIREMENTS

 Number of Notes: 32 simultaneous notes

 MIDI Channels: 16

  - Simultaneous Melodic Instruments = up to 16 (all Channels)

  - Simultaneous Percussion Kits = up to 2 (Channel 10/11)

SUPPORTED CONTROL CHANGE MESSAGES (Some Optional)

 - Bank Select (cc#0/32)

 - Modulation Depth (cc#1)

 - Portamento Time (cc#5)

 - Channel Volume (cc#7)

 - Pan (cc#10)

 - Expression (cc#11)

 - Hold1 (Damper) (cc#64)

 - Portamento ON/OFF (cc#65)

 - Sostenuto (cc#66)

 - Soft (cc#67)

 - Filter Resonance (Timbre/Harmonic Intensity) (cc#71)

 - Release Time (cc#72)

 - Attack time (cc#73)

 - Brightness (cc#74)

 - Decay Time (cc#75)

 - Vibrato Rate (cc#76)

 - Vibrato Depth (cc#77)

 - Vibrato Delay (cc#78)

 - Reverb Send Level (cc#91)

 - Chorus Send Level (cc#93)

 - Data Entry (cc#6/38)

 - RPN LSB/MSB (cc#100/101)

SUPPORTED RPNs (Registered Parameter Numbers)

 - Pitch Bend Sensitivity

 - Channel Fine Tune

 - Channel Coarse Tune

 - New! Modulation Depth Range (Vibrato Depth Range)

 - RPN NULL

SUPPORTED UNIVERSAL SYSTEM EXCLUSIVE MESSAGES

 - Master Volume

 - New! Master Fine Tuning

 - New! Master Coarse Tuning

 - New! Reverb Type

 - New! Reverb Time

 - New! Chorus Type

 - New! Chorus Mod Rate

 - New! Chorus Mod Depth

 - New! Chorus Feedback

 - New! Chorus Send to Reverb

 - New! Controller Destination Setting

 - New! Scale/Octave Tuning Adjust

 - New! Key-Based Instrument Controllers

 - New! GM2 System On

GM 2 INSTRUMENT SOUND SET

GM 2 PERCUSSION SOUND SET