CLM was actually made by the author of s7, who is one of the godfather's of computer music. You could check out Common Music 3 which was a big inspiration for S4M and also runs s7, but it is unfortunately non longer actively developed as the author now has to teach using Python.

Other Lisp music related things include Incudine, Slippery Chicken, the Snd editor, MozLib (CL stuff for Max).