In contract, orchestral player (5)
I believe the answer is:
actor
'player' is the definition.
(synonyms)
'in contract orchestral' is the wordplay.
'in' indicates a hidden word.
'ACTOR' is hidden in the letters of 'contract orchestral'.
(Other definitions for actor that I've seen before include "Luvvy" , "one to take on roles" , "Dramatic artist" , "Theatre player" , "Theatrical player" .)