+pushToTag =
+#(define-music-function (parser location tag more music)
+ (symbol? ly:music? ly:music?)
+ (_i "Add @var{more} to the front of @code{elements} of all music
+expressions in @var{music} that are tagged with @var{tag}.")
+ (music-map (lambda (m)
+ (if (memq tag (ly:music-property m 'tags))
+ (set! (ly:music-property m 'elements)
+ (cons more (ly:music-property m 'elements))))
+ m)
+ music))
+