Very cool. I'm working on something similar, for composing songs with both note-playing instruments and drum instruments. The format is TOML-based, and for melody I was inspired by strudel, but I had considered using ABC notation as well. The home page has an example of the format, and some demo songs: https://songformat.com
I definitely considered stuff like that but in the end decided to have every note spelled out.
I might reconsider though! Right now it's really annoying to have reaaally long lines of `kd/2` ad infinitum to write double bass.
I'm split between three options right now:
1. Just add multipliers like you did (`kd/2 * 16`), but I feel that makes it less "music" and more "program".
2. Special syntax sugar just for well known patterns that are repeated in many songs, like `dkdk` expands to a full bar of double bass, or xxx expands to one full bar of 8th notes on the hi-hats.
3. Have the user define custom pattern on their own, like `xxx = x x x x x x x x`, like C macros.
