Ask about Jamaican music (3)
I believe the answer is:
ska
'jamaican music' is the definition.
(Jamaican musical genre)
'ask about' is the wordplay.
'about' indicates anagramming the letters.
'ask' anagrammed gives 'SKA'.
(Other definitions for ska that I've seen before include "popular music" , "Music genre" , "Dancehall music" , "Noted genre" , "Jamaican music, forerunner of reggae" .)