Choose quietly to make an allusion (6)
I believe the answer is:
prefer
'choose' is the definition.
(I know that choose can be written as prefer)
'quietly to make an allusion' is the wordplay.
'quietly' becomes 'p' (p for piano and quiet).
'to make an allusion' becomes 'refer' (I've seen this in another clue).
'p'+'refer'='PREFER'
(Other definitions for prefer that I've seen before include "Like (something) better than another" , "support" , "Value more highly" , "Favour, like better" , "Choose as more desirable, like better" .)