Professor of church music (5)
I believe the answer is:
chair
'professor' is the definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'church music' is the wordplay.
'church' becomes 'ch' (common abbreviation).
'music' becomes 'air' (air is a kind of music).
'ch'+'air'='CHAIR'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for chair that I've seen before include "Movable seat" , "director at meeting" , "Seat for one person" , "Backed seat for one" , "Supporter" .)