Featured in choir, perhaps, part of diocesan group (4)
I believe the answer is:
sang
'featured in choir perhaps' is the definition.
(as in singing as part of a choir)
'part of diocesan group' is the wordplay.
'part of' indicates the answer is hidden within the clue.
'SANG' is hidden in the letters of 'diocesan group'.
(Other definitions for sang that I've seen before include "Celebrated" , "Chorused" , "Was in a choir" , "Did numbers" , "Took part in a vocal performance" .)