General MIDI & General MIDI 2 Overview

If you have been around a keyboard or digital piano within the past few years, you probably have heard references to General MIDI and General MIDI 2. How does that fit in with MIDI?  Is there a difference, and should you care?  The answer depends on if you plan to share your MIDI work with other musicians or if you will be saving the data just for your own use. If it is the latter, then you really can save the file in any format you want since you will be the only person using the file.

If you would like to take a MIDI file of one of your performances and share it with others, then you will want to follow the basic rules of General MIDI, usually referred to as GM or GM2, which is short for General MIDI 2.

Just about any keyboard, digital piano, or organ made over the past couple of years will be GM aware, and more than likely will be GM2 capable. To verify that your keyboard supports GM or GM2 first, look in your owner’s manual. You should also be able to find the GM or GM2 logos on your keyboard.

Both GM and GM2 formats are nothing more than a standard that allows any piece of equipment displaying the GM or GM2 logo to understand and share data in those formats. That means if you record a song and you select an Acoustic Bass, Piano, and Standard Drum Set, you can expect the file to playback on any GM/GM2 instrument with the same instruments – Acoustic Bass, Piano, and Standard Drum Set. While those instruments’ sound quality may vary from vendor to vendor, you can expect them to be reasonably close.

General MIDI, created back in the 1980s, is still in use today. There are 128 instruments in the General MIDI patch map. The instruments are grouped into various instrument families.

General MIDI Level 1 Instrument Families

Program NumberFamily NameProgram NumberFamily Name
9-16Chromatic Percussion73-80Pipe
17-24Organ81-88Synth Lead
25-32Guitar89-96Synth Pad
33-40Bass97-104Synth Effects
57-64Brass121-128Sound Effects

General MIDI Level 1 Instrument Patch Map

Program NumberInstrument NameProgram NumberInstrument Name
1Acoustic Grand Piano65Soprano Sax
2Bright Acoustic Piano66Alto Sax
3Electric Grand Piano67Tenor Sax
4Honky-tonk Piano68Baritone Sax
5Electric Piano 169Oboe
6Electric Piano 270English Horn
11Music Box75Recorder
12Vibraphone76Pan Flute
13Marimba77Blown Bottle
15Tubular Bells79Whistle
17Drawbar Organ81Lead 1 (square)
18Percussive Organ82Lead 2 (sawtooth)
19Rock Organ83Lead 3 (calliope)
20Church Organ84Lead 4 (chiff)
21Reed Organ85Lead 5 (charang)
22Accordion86Lead 6 (voice)
23Harmonica87Lead 7 (fifths)
24Tango Accordion88Lead 8 (bass + lead)
25Acoustic Guitar (nylon)89Pad 1 (new age)
26Acoustic Guitar (steel)90Pad 2 (warm)
27Electric Guitar (jazz)91Pad 3 (polysynth)
28Electric Guitar (clean)92Pad 4 (choir)
29Electric Guitar (muted)93Pad 5 (bowed)
30Overdriven Guitar94Pad 6 (metallic)
31Distortion Guitar95Pad 7 (halo)
32Guitar harmonics96Pad 8 (sweep)
33Acoustic Bass97FX 1 (rain)
34Electric Bass (finger)98FX 2 (soundtrack)
35Electric Bass (pick)99FX 3 (crystal)
36Fretless Bass100FX 4 (atmosphere)
37Slap Bass 1101FX 5 (brightness)
38Slap Bass 2102FX 6 (goblins)
39Synth Bass 1103FX 7 (echoes)
40Synth Bass 2104FX 8 (sci-fi)
45Tremolo Strings109Kalimba
46Pizzicato Strings110Bag pipe
47Orchestral Harp111Fiddle
49String Ensemble 1113Tinkle Bell
50String Ensemble 2114Agogo
51SynthStrings 1115Steel Drums
52SynthStrings 2116Woodblock
53Choir Aahs117Taiko Drum
54Voice Oohs118Melodic Tom
55Synth Voice119Synth Drum
56Orchestra Hit120Reverse Cymbal
57Trumpet121Guitar Fret Noise
58Trombone122Breath Noise
60Muted Trumpet124Bird Tweet
61French Horn125Telephone Ring
62Brass Section126Helicopter
63SynthBrass 1127Applause
64SynthBrass 2128Gunshot

In the percussion sounds, each will be located at the same note location. For example, note number 35 would be the bass drum. When you play note 35 on MIDI channel 10, and you are in GM mode, you will always hear a bass drum.

General MIDI Level 1 Percussion Key Map

Note NumberPercussion SoundNote NumberPercussion Sound
35Acoustic Bass Drum59Ride Cymbal 2
36Bass Drum 160Hi Bongo
37Side Stick61Low Bongo
38Acoustic Snare62Mute Hi Conga
39Hand Clap63Open Hi Conga
40Electric Snare64Low Conga
41Low Floor Tom65High Timbale
42Closed Hi Hat66Low Timbale
43High Floor Tom67High Agogo
44Pedal Hi-Hat68Low Agogo
45Low Tom69Cabasa
46Open Hi-Hat70Maracas
47Low-Mid Tom71Short Whistle
48Hi-Mid Tom72Long Whistle
49Crash Cymbal 173Short Guiro
50High Tom74Long Guiro
51Ride Cymbal 175Claves
52Chinese Cymbal76Hi Wood Block
53Ride Bell77Low Wood Block
54Tambourine78Mute Cuica
55Splash Cymbal79Open Cuica
56Cowbell80Mute Triangle
57Crash Cymbal 281Open Triangle

Although you have access to 128 instruments in General MIDI mode, you will only have access to one drum kit, the standard drum kit.

This is a perfect lead-in for GM2 or General MIDI 2. Introduced in 1999 as an extension to the original GM format, GM2 allows both MIDI channels 10 and 11 for percussion parts along with the essential MIDI bank change command.

Let’s go back to the Bass Drum example. In General MIDI, we mentioned that you could only access the standard drum kit. You probably have multiple drum kits on your instrument. Depending on the type of music you are performing, selecting the correct drum kit can make or break the performance. To access a different drum kit, you need to issue a bank change command and the program number of the desired drum kit. In GM2 mode, nine drum kits are available.

GM2 Drum Kits

Program NumberKit
0Standard Set
1Room Set
2Power Set
3Electric Set
4Analog Set
5Jazz Set
6Brush Set
7Orchestra Set
8SFX Set

The same thing is true for your instrument patches. You will be able to select additional banks of instruments by using the bank select command. In GM2, the number of instruments you will have access to grows to 256 instruments compared to only 128 in GM mode. The additional instruments fall under the same instrument families found in GM. For example, in the piano family, you will find Detuned Electric Piano located in Bank 1 Program Number 5 and Detuned Electric Piano2 located in Bank 1 Program Number 6. This is in addition to the Electric Piano 1 and Electric Piano 2 piano offered in GM mode, located in Bank 0 in the same program number locations (5 and 6).

To summarize, GM2 files will offer a wider palette of sounds and supporting effects, along with additional control features allowing more editing of the final musical performance.

So what does all this sound like? Take a listen to a short sample of a jazz arrangement of Bach Prelude XV, which is a General MIDI format sequence using the instruments mentioned earlier, Acoustic Bass, Piano, and Standard Drum Set.

Since this file is saved in General MIDI format, it will play the correct instruments regardless of the manufacturer of the GM capable MIDI device it is played back on. That could be the sound card in your computer or your multi-thousand dollar keyboard. The only difference in the final listening experience will be the quality of the sampled instruments your MIDI device offers.

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