Jazz fan hosting simple show (7)
I believe the answer is:
cabaret
'show' is the definition.
(I know that cabaret is a type of show)
'jazz fan hosting simple' is the wordplay.
'jazz fan' becomes 'cat' (slang term for a jazz fan).
'hosting' means one lot of letters goes inside another (inserted letters are welcomed in or hosted).
'simple' becomes 'bare' (synonyms).
'cat' going around 'bare' is 'CABARET'.
(Other definitions for cabaret that I've seen before include "Musical - nightclub entertainment" , "goes on in nightclub?" , "Entertainment provided in a nightclub" , "Entertainment at restaurant" , "Entertainment at night club" .)