Die Instrumente sind in die folgenden 16 Gruppen eingeteilt:
| Inst. # | Family | Inst. # | Family |
| 1-8 | Piano | 65-72 | Reed |
| 9-16 | Chromatic Percussion | 73-80 | Pipe |
| 17-24 | Organ | 80-88 | Synth Lead |
| 25-32 | Guitar | 89-96 | Synth Pad |
| 33-42 | Bass | 97-104 | Synth Effects |
| 43-50 | Strings | 105-112 | Ethnic |
| 51-58 | Ensemble | 113-120 | Percussive |
| 59-64 | Brass | 120-128 | Sound Effects |
Jede dieser Gruppen enthält 8 Instrumente / Klänge.
Die folgende Tabelle enthält die Instrumentenbelegung nach GM1 Standard.
| Inst. # | Name | Inst. # | Name | Inst. # | Name | Inst. # | Name |
| 1. | Acoustic Grand Piano | 9. | Celesta | 17. | Drawbar Organ | 25. | Acoustic Guitar (nylon) |
| 2. | Bright Acoustic Piano | 10. | Glockenspiel | 18. | Percussive Organ | 26. | Acoustic Guitar (steel) |
| 3. | Electric Grand Piano | 11. | Music Box | 19. | Rock Organ | 27. | Electric Guitar (jazz) |
| 4. | Honky-Tonk Piano | 12. | Vibraphone | 20. | Church Organ | 28. | Electric Guitar (clean) |
| 5. | Electric Piano 1 | 13. | Marimba | 21. | Reed Organ | 29. | Electric Guitar (muted) |
| 6. | Electric Piano 2 | 14. | Xylophone | 22. | Accordion | 30. | Overdriven Guitar |
| 7. | Harpsichord | 15. | Tubular Bells | 23. | Harmonica | 31. | Distortion Guitar |
| 8. | Clavi | 16. | Dulcimer | 24. | Tango Accordion | 32. | Guitar Harmonics |
| 33. | Acoustic Bass | 41. | Violin | 49. | String Ensemble 1 | 57. | Trumpet |
| 34. | Electric Bass (finger) | 42. | Viola | 50. | String Ensemble 2 | 58. | Trombone |
| 35. | Electric Bass (pick) | 43. | Cello | 51. | SynthStrings 1 | 59. | Tuba |
| 36. | Fretless Bass | 44. | Contrabass | 52. | SynthStrings 2 | 60. | Muted Trumpet |
| 37. | Slap Bass 1 | 45. | Tremolo Strings | 53. | Choir Aahs | 61. | French Horn |
| 38. | Slap Bass 2 | 46. | Pizzicato Strings | 54. | Voice Oohs | 62. | Brass Section |
| 39. | Synth Bass 1 | 47. | Orchestral Harp | 55. | Synth Voice | 63. | SynthBrass 1 |
| 40. | Synth Bass 2 | 48. | Timpani | 56. | Orchestra Hit | 64. | SynthBrass 2 |
| 65. | Soprano Sax | 73. | Piccolo | 81. | Lead 1 (square) | 89. | Pad 1 (new age) |
| 66. | Alto Sax | 74. | Flute | 82. | Lead 2 (sawtooth) | 90. | Pad 2 (warm) |
| 67. | Tenor Sax | 75. | Recorder | 83. | Lead 3 (calliope) | 91. | Pad 3 (polysynth) |
| 68. | Baritone Sax | 76. | Pan Flute | 84. | Lead 4 (chiff) | 92. | Pad 4 (choir) |
| 69. | Oboe | 77. | Blown Bottle | 85. | Lead 5 (charang) | 93. | Pad 5 (bowed) |
| 70. | English Horn | 78. | Shakuhachi | 86. | Lead 6 (voice) | 94. | Pad 6 (metallic) |
| 71. | Bassoon | 79. | Whistle | 87. | Lead 7 (fifths) | 95. | Pad 7 (halo) |
| 72. | Clarinet | 80. | Ocarina | 88. | Lead 8 (bass + lead) | 96. | Pad 8 (sweep) |
| 97. | FX 1 (rain) | 105. | Sitar | 113. | Tinkle Bell | 121. | Guitar Fret Noise |
| 98. | FX 2 (soundtrack) | 106. | Banjo | 114. | Agogo | 122. | Breath Noise |
| 99. | FX 3 (crystal) | 107. | Shamisen | 115. | Steel Drums | 123. | Seashore |
| 100. | FX 4 (atmosphere) | 108. | Koto | 116. | Woodblock | 124. | Bird Tweet |
| 101. | FX 5 (brightness) | 109. | Kalimba | 117. | Taiko Drum | 125. | Telephone Ring |
| 102. | FX 6 (goblins) | 110. | Bag Pipe | 118. | Melodic Tom | 126. | Helicopter |
| 103. | FX 7 (echoes) | 111. | Fiddle | 119. | Synth Drum | 127. | Applause |
| 104. | FX 8 (sci-fi) | 112. | Shanai | 120. | Reverse Cymbal | 128. | Gunshot |