(number->string duration)))
((mensural)
(string-append (number->string duration) (symbol->string style)))
+ ((petrucci)
+ (if (< duration 0)
+ (string-append (number->string duration) "mensural")
+ (string-append (number->string duration) (symbol->string style))))
((neomensural)
(string-append (number->string duration) (symbol->string style)))
((default)