Select a quiet property (7)
I believe the answer is:
appoint
'select' is the definition.
(I've seen this in another clue)
'a quiet property' is the wordplay.
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'property' becomes 'point' (point is a kind of property).
'a'+'p'+'point'='APPOINT'
(Other definitions for appoint that I've seen before include "Assign to a duty" , "Determine (a time/place)" , "Assign position to" , "Delegate" , "Establish" .)