Book deals quietly removed (4)
I believe the answer is:
acts
'book' is the definition.
(book of the Bible)
'deals quietly removed' is the wordplay.
'deals' becomes 'pacts' (a pact is a deal or agreement).
'quietly' becomes 'p' (p for piano and quiet).
'removed' suggests deleting specific letters.
'pacts' with 'p' taken out is 'ACTS'.
(Other definitions for acts that I've seen before include "NT book; laws" , "Dramatic parts" , "placed before Romans?" , "Does something" , "Cast down by deeds" .)