Sacred music and, I would add, charity (6)
I believe the answer is:
psalms
'sacred music' is the definition.
(I've seen this in another clue)
'i would add charity' is the wordplay.
'i would add' becomes 'PS' (as in a PS in a letter).
'charity' becomes 'alms' (alms is a kind of charity).
'ps'+'alms'='PSALMS'
'and' acts as a link.
(Other definitions for psalms that I've seen before include "Sacred songs or hymns" , "Sacred songs of praise" , "David's hymns" , "in the Bible?" , "They're heard in church" .)