Reggae precursor (3)
I believe the answer is:
'reggae precursor' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ska that I've seen before include "Jamaican music, forerunner of reggae" , "Jamaican music style" , "Dancehall music" , "popular music" , "Noted genre" .)