Some grandpa interviewing artist (7)
I believe the answer is:
painter
'artist' is the definition.
(type of artist)
'some grandpa interviewing' is the wordplay.
'some' indicates a hidden word (some parts of the word are used).
'PAINTER' is hidden within 'grandpa interviewing'.
(Other definitions for painter that I've seen before include "a line connected to a boat" , "keeps a boat by the bank" , "Artist's rope for fastening a boat?" , "What Rolf Harris was allowed to do" , "Shipping line" .)