Salesman turns up with past actor (9)
I believe the answer is:
'actor' is the definition.
'salesman turns up with past' is the wordplay.
'salesman' becomes 'rep' (I've seen this before).
'turns up' says the letters should be written in reverse.
'with' is a charade indicator (letters next to each other).
'past' becomes 'former' ('former' can be similar in meaning to 'past'**).
'rep' back-to-front is 'per'.
(Other definitions for performer that I've seen before include "Entertainer" , "clown possibly" , "Fred Astaire, say" , "Such as a musician or actor" , "artist" .)