Note On and Note Off
Note On starts a note and Note Off ends it, and the way it ends shapes overlaps and drum decay.
Related
Every note needs two messages, one to start and one to stop. How it stops decides staccato, legato and the length of a drum hit.
The problem
A Note On without an end leaves a stuck note, while an early Note Off cuts the tail. Overlapping the same pitch is harder, since the first end may close the second.
Protocol or message
Note On uses 0x9n with key and velocity, Note Off uses 0x8n. A Note On with velocity 0 counts as Note Off, an old byte-saving convention. Most instruments ignore the release velocity. When the same key repeats, the first note must end before the second starts, or the instrument cannot pair ends with starts. Events are ordered by delta time, so an end can follow the next start.
Settings and practice
Hold piano notes with CC64 rather than a stretched Note Off. Drums usually ignore Note Off and play the whole sample after a trigger. For staccato, move the end earlier instead of lowering velocity.
What to listen for
Staccato and legato differ at the moment of release, and twenty milliseconds changes what you hear. When an end closes the wrong note, the tail disappears.
Common misunderstandings
Release velocity is not volume. Not every instrument accepts velocity 0 as Note Off. Note length is not loudness.
Listen in the library
All tracks from midicn-lib — inline badge is the license tier (C1 commercial / C2 non-commercial / C3 study only).
Sources
- MIDI 1.0 规范对 Note On 与 Note Off 的定义，依 MMA 公开规范核查，未抄文本
- 力度 0 的旧约定与重叠音处理，依通行音序器文档核查，未抄文本
Used for fact-checking only; all prose is original.