Sorry for not tracking this further down - I suspected that (voicelim ...) was erroneously called instead of (instr-voicelim ...), but I did not really succeed... I have to first of all read more of your code.
Thanks, it'll be fixed in the next cvs commit. I might change "voicelim" to something like "simultlim" since voicelim isn't really correct.
The fix is in (defparameter +instr-type+ in data.lisp, which needs to be:
(defparameter +instr-type+ `(with-error* (instr "~~A of INSTR struct ~S" ,#'instr-sym) (struct* instr (instr-sym ... (instr-clefs ... (instr-staves ... (instr-minp ... (instr-maxp ... (instr-voicelim ... (instr-tpose ... (instr-cleflegls ... (instr-8uplegls ... (instr-8dnlegls ... (instr-percs ...