Rewarded with quiet assistance (4)
I believe the answer is:
paid
'rewarded' is the definition.
(I've seen this in another clue)
'with quiet assistance' is the wordplay.
'with' says to put letters next to each other.
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'assistance' becomes 'aid' (synonyms).
'p' next to 'aid' is 'PAID'.
(Other definitions for paid that I've seen before include "Forked out" , "Settled financially" , "See 12" , "Remunerated" , "Settled the bill" .)