+harmonicsOn =
+#(define-music-function (parser location) ()
+ (_i "Set the default note head style to a diamond-shaped style.")
+ (override-head-style 'NoteHead 'harmonic))
+harmonicsOff = \defaultNoteHeads
+harmonicNote =
+#(define-music-function (parser location note) (ly:music?)
+ (_i "Print @var{note} with a diamond-shaped note head.")
+ (style-note-heads 'NoteHead 'harmonic note))