GM Drum Map
On channel 10 each key number is a percussion instrument, and the program number has no say.
Related
On the drum channel, a key number is an instrument name. Habit from melodic writing has to change here.
The problem
Drums have no pitch, so one key off turns a snare into a tom, and a drum part sent to another channel becomes a piano line.
Protocol or message
GM fixes channel 10 as drums, with keys 35 to 81 mapped to percussion. 36 is kick, 38 snare, 42 closed hat, 46 open hat, 49 crash, 51 ride, 39 clap and 37 side stick. An instrument triggers its sample on Note On and usually ignores Note Off. Keys such as 22 sit outside the GM table and appear only in private hardware maps. CC4 often controls the hi-hat pedal.
Settings and practice
Always write drums on channel 10. Use key numbers rather than note names. Do not place closed and open hats at the same instant. Velocity layers shape the snare. Leave room for kick and bass in the spectrum.
What to listen for
Closed hat 42 and open hat 46 differ in tail length. Kick 36 and 35 differ in low-end weight. One wrong key makes a pattern muddy at once.
Common misunderstandings
The drum channel can hold melody, but the instrument reads it as drum keys. Channel 10 is not the tenth track. Note Off rarely matters for drums.
Listen in the library
All tracks from midicn-lib — inline badge is the license tier (C1 commercial / C2 non-commercial / C3 study only).
Sources
- 通用 MIDI 规范对打击通道与键号的映射，依 MMA 公开规范核查，未抄文本
- 本库鼓轨的键号统计，由本地 SMF 解析脚本核对，数值随文件而定
Used for fact-checking only; all prose is original.