Repeated rhythmic phrase (5)
I believe the answer is:
chant
'repeated rhythmic phrase' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for chant that I've seen before include "Type of singing with a simple melody and several words sung on one note" , "Gregorian song?" , "Intone (psalm)" , "Mantra" , "Toil" .)