Ok, I thought you had compiled the music.lisp as part of a build of the CLM package. I'm not familiar with CLM, but the documentation says:
How To Build CLM: In general start lisp and (load "all.lisp").
Have you done this? The README.clm file has full instructions.
Yes, I have and the load/build failed during the compile of mus.lisp. I provided the stack trace from a call to compile-file since it gave the same compile error.
To me, it looks like it's a problem with the bes-i0 function; however, you will probably get better advice on a CLM mailing list.
Instead of using compile-file at the REPL in SLIME, try just doing C-c M-k when you are in the mus.lisp source file. That will compile the file and produce a list of compile errors in a separate *compiler-notes* buffer. In the *compiler-notes* buffer, you can place your cursor on the particular error message and press Enter. That will take you to the place in the mus.lisp source file where the compilation error occured.
I forgot to say that once you have done that, M-n and M-p take you to the next/previous compilation note. That was why I asked whether M-n worked in my first reply to you.
- Bill