(iterator-ctor ,procedure? "Function to construct a
@code{music-event-iterator} object for this music.")
- (label ,markup? "Label of a mark.")
+ (label ,number-or-markup? "Label of a mark.")
(last-pitch ,ly:pitch? "The last pitch after relativization.")
(length ,ly:moment? "The duration of this music.")
(length-callback ,procedure? "How to compute the duration of this music.