\version "2.19.17"

% would be placed in the actual music file
clef-set = low

#(define high-clefs '("G" "mezzosoprano" "C" "varbaritone"))
#(define low-clefs '("soprano" "C" "tenor" "F"))
#(define modern-clefs '("G" "G" "G_8" "F"))
#(define clef-set-alist `((high . ,high-clefs)
                    (low . ,low-clefs)
                    (modern . ,modern-clefs)))

% test a bit from define-scheme-function
#(display (assoc-get clef-set clef-set-alist))