(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.
(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.