Quiet atmosphere in match (4)
I believe the answer is:
pair
'match' is the definition.
('pair' can be a synonym of 'match')
'quiet atmosphere' is the wordplay.
'quiet' becomes 'p' (music symbol for 'piano').
'atmosphere' becomes 'air' ('air' can be a synonym of 'atmosphere'**).
'p'+'air'='PAIR'
'in' is the link.
(Other definitions for pair that I've seen before include "2" , "Brace, couple" , "Agreement to avoid division" , "Two of a similar type" , "players of duet?" .)