This function lets you write rhythms using a beat/space formulism outside the def-instrument-rhythm score definition. Use it as an alternative to writing in note-lengths:
Notice the difference in the symbol mapping between def-rhythm and beat/space.
(def-instrument-rhythm
bass 1/16 "- -- -" '(a b c d))
; a bc d
(beat/space '48 "- -- -")
; abcdabcd
; a ab d
Many ethnic musics, notably Javanese Gamelan and Ghanian drumming, as well as western rock and systems music, use this beat/space formulism for rhythm construction. Also, the form of the symbol mapping used in beat/space is probably more representative of these styles of music.
Another way to get similar beat/space results is to use the def-rhythm-mask.