\version "2.19.53"

musicFunctionDummy = #(define-music-function (mus) (ly:music?) mus)

addToplevelMusicFunctions =
#(define-scheme-function (names) (symbol-list-or-symbol?)
   (let* ((name-list (if (list? names) names (list names)))
          (lookup-function (lambda (name) (let ((fn (ly:parser-lookup name)))
                                            (if (equal? fn '())
                                                musicFunctionDummy
                                                fn))))
          (fn-list (map lookup-function name-list)))
     (set! toplevel-music-functions (append fn-list toplevel-music-functions))))