Choral piece assembled around Biblical texts (5)
I believe the answer is:
motet
'choral piece' is the definition.
(I've seen this in another clue)
'assembled around biblical texts' is the wordplay.
'assembled' becomes 'met' ('meet' can be a synonym of 'assemble').
'around' is an insertion indicator.
'biblical texts' becomes 'ot' (I can't justify this - if you can you should believe this answer much more).
'met' enclosing 'ot' is 'MOTET'.
Can you help me to learn more?
(Other definitions for motet that I've seen before include "Church choral composition" , "Short piece of church choral music" , "Unaccompanied choral composition with sacred lyrics" , "Certain one is morally superior" , "Short sacred choral piece" .)