Brooches quiet in style (6)
I believe the answer is:
clasps
'brooches' is the definition.
('clasp' can be a synonym of 'brooch')
'quiet in style' is the wordplay.
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'in' indicates putting letters inside.
'style' becomes 'class' (I've seen this in another clue).
'p' inserted within 'class' is 'CLASPS'.
(Other definitions for clasps that I've seen before include "Embraces, hugs" , "Holds the fastenings to one's bosom" , "Holds or embraces closely" , "Holds tightly" , "Embraces; fastenings" .)