Kind of rock or jazz (4)
I believe the answer is:
acid
'kind of rock or jazz' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for acid that I've seen before include "Polluted precipitation" , "Sarcastic (could be sulphuric?)" , "- - -drop, sweet" , "Chemical compound" , "Sour (substance)" .)