This printing function was established in 2005, but where it is used,
nowadays one does not need to use Scheme for indicating strings, ever.
(define-public (value->lily-string arg)
(cond ((ly:music? arg)
(music->lily-string arg))
(define-public (value->lily-string arg)
(cond ((ly:music? arg)
(music->lily-string arg))
- ((string? arg)
- (format #f "#~s" arg))
((markup? arg)
(markup->lily-string arg))
((ly:duration? arg)
((markup? arg)
(markup->lily-string arg))
((ly:duration? arg)