Prompt and quiet staff (4)
I believe the answer is:
prod
'prompt' is the definition.
(I've seen this in another clue)
'quiet staff' is the wordplay.
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'staff' becomes 'rod' (both can mean a stick or cane).
'p'+'rod'='PROD'
'and' is the link.
(Other definitions for prod that I've seen before include "Poke, stimulate into action" , "Induce action (with stick etc?)" , "Incite to action (with a stick?)" , "Give a reminder" , "Poke; reminder" .)