Fountain of jazz (4)
I believe the answer is:
pete
'fountain of jazz' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for pete that I've seen before include "- Sampras, tennis star" , "- Doherty, Babyshambles singer" , "-- Sampras, tennis ace" , "Small 14 [PETER JONES]" , "- Seeger, US folk singer" .)