Backers singing about god in Luxor (6)
I believe the answer is:
chorus
'backers singing' is the definition.
(chorus can mean a group of backing singers)
'about god in luxor' is the wordplay.
'about' becomes 'c' (circa).
'god in luxor' becomes 'Horus' (Egyptian god - Luxor is in Egypt).
'c'+'horus'='CHORUS'
(Other definitions for chorus that I've seen before include "People singing" , "Supporting singers and dancers" , "It joins a soloist in parts of songs" , "Vocal composition" , "Section of song" .)