NRTDRV MAN EN SYNTAX MUSICALSCALE
From MSX MUSIC WIKI
Musical scales
NRTDRV supports ordinary [WikiNote i.e English notation like] MML, thus from "c" to "b" and "r(rest)".
Example: cdefgab Plays "cdefgab".
"+" after scale means sharp and "-" after scale means flat.
Example: c c+ d e- e Plays c c sharp d e flat e
"Double sharps" and "double flat" are not available. If you write "c++", it is recognized as "c+(sharp)" and "+(add length)". For example "l8 c++" is recognized as "c+8+8" and "c+4".
You can omit sharps and flats with key signatures. Refer "Key signature commands" for details.