Quietly mention the club (6)
I believe the answer is:
putter
'club' is the definition.
(a golf club)
'quietly mention' is the wordplay.
'quietly' becomes 'p' (p for piano and quiet).
'mention' becomes 'utter' (I've seen this in another clue).
'p'+'utter'='PUTTER'
'the' acts as a link.
(Other definitions for putter that I've seen before include "Golf-club" , "Type of golf club" , "Club used on the green" , "Golf club used on greens" , "Club to use on the green" .)