Request for quiet field (4)
I believe the answer is:
plea
'request' is the definition.
(I know that plea is a type of appeal)
'quiet field' is the wordplay.
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'field' becomes 'lea' (lea can mean a meadow or field of grass).
'p'+'lea'='PLEA'
'for' acts as a link.
(Other definitions for plea that I've seen before include "Leap (anag.)" , "Excuse; petition" , "Excuse - pretext" , "Intercession" , "Defence - excuse - appeal" .)