Quiet chap, this friend? (3)
I believe the answer is:
pal
'this friend?' is the definition.
(pal is a kind of friend)
'quiet chap' is the wordplay.
'quiet' becomes 'p' (music symbol for 'piano').
'chap' becomes 'al' (**).
'p'+'al'='PAL'
(Other definitions for pal that I've seen before include "China" , "Friend (colloq.)" , "Close friend" , "Mate, buddy" , "Buddy, chum" .)