Jazz phrase (4)
I believe the answer is:
riff
'jazz phrase' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for riff that I've seen before include "Short repeated jazz figure" , "bit of music" , "Short repeated phrase in popular music or jazz" , "Short repeated phrase (in jazz, etc)" , "Berber - repeated jazz phrase" .)