Priest playing in band (6)
I believe the answer is:
stripe
'band' is the definition.
(I know that band can be written as stripe)
'priest playing' is the wordplay.
'playing' is an anagram indicator.
'priest' is an anagram of 'STRIPE'.
'in' is the link.
(Other definitions for stripe that I've seen before include "Sleeve badge showing military rank" , "bar" , "Length of material, maybe showing rank" , "Priest (anag)" , "Long band of a different colour" .)