(ly:add-interface
'glissando-interface
"A glissando."
- '())
+ '(glissando-index))
(ly:add-interface
'grace-spacing-interface
"A key cancellation."
'())
+(ly:add-interface
+ 'ligature-head-interface
+ "A note head that can become part of a ligature."
+ '())
+
(ly:add-interface
'ligature-bracket-interface
"A bracket indicating a ligature in the original edition."