+displayMusic =
+#(define-music-function (parser location music) (ly:music?)
+ (newline)
+ (display-scheme-music music)
+ music)
+
+featherDurations=
+#(define-music-function (parser location factor argument) (ly:moment? ly:music?)
+ (_i "Rearrange durations in ARGUMENT so there is an
+acceleration/deceleration. ")
+
+ (let*
+ ((orig-duration (ly:music-length argument))
+ (multiplier (ly:make-moment 1 1)))
+
+ (music-map
+ (lambda (mus)
+ (if (and (eq? (ly:music-property mus 'name) 'EventChord)
+ (< 0 (ly:moment-main-denominator (ly:music-length mus))))
+ (begin
+ (ly:music-compress mus multiplier)
+ (set! multiplier (ly:moment-mul factor multiplier)))
+ )
+ mus)
+ argument)
+
+ (ly:music-compress
+ argument
+ (ly:moment-div orig-duration (ly:music-length argument)))
+
+ argument))
+
+grace =
+#(def-grace-function startGraceMusic stopGraceMusic)
+
+
+"instrument-definitions" = #'()
+
+addInstrumentDefinition =
+#(define-music-function
+ (parser location name lst) (string? list?)
+
+ (set! instrument-definitions (acons name lst instrument-definitions))
+
+ (make-music 'SequentialMusic 'void #t))
+
+
+instrumentSwitch =
+#(define-music-function
+ (parser location name) (string?)
+ (let*
+ ((handle (assoc name instrument-definitions))
+ (instrument-def (if handle (cdr handle) '()))
+ )
+
+ (if (not handle)
+ (ly:input-message "No such instrument: ~a" name))
+ (context-spec-music
+ (make-music 'SimultaneousMusic
+ 'elements
+ (map (lambda (kv)
+ (make-property-set
+ (car kv)
+ (cdr kv)))
+ instrument-def))
+ 'Staff)))
+
+
+keepWithTag =
+#(define-music-function
+ (parser location tag music) (symbol? ly:music?)
+ (music-filter
+ (lambda (m)
+ (let* ((tags (ly:music-property m 'tags))
+ (res (memq tag tags)))
+ (or
+ (eq? tags '())
+ res)))
+ music))
+
+
+
+killCues =
+#(define-music-function
+ (parser location music)
+ (ly:music?)
+ (music-map
+ (lambda (mus)
+ (if (string? (ly:music-property mus 'quoted-music-name))
+ (ly:music-property mus 'element)
+ mus)) music))
+
+
+makeClusters =
+#(define-music-function
+ (parser location arg) (ly:music?)
+ (music-map note-to-cluster arg))
+
+musicMap =
+#(define-music-function (parser location proc mus) (procedure? ly:music?)
+ (music-map proc mus))
+
+
+
+oldaddlyrics =
+#(define-music-function (parser location music lyrics) (ly:music? ly:music?)
+
+ (make-music 'OldLyricCombineMusic
+ 'origin location
+ 'elements (list music lyrics)))
+