There was a music language made for the Danish GIER machine, made in 1971 (at least the 2nd edition of the handbook is from there)

The handbook for the language is sadly only in Danish so it might not be super interesting: https://datamuseum.dk/bits/30002486

Here is the code for movement 1 and 2 of Eine Kleine Nachtmusik: https://datamuseum.dk/aa/gier/30000644.html