Performers walk in the auditorium (6)
I believe the answer is:
troupe
'performers' is the definition.
(eg a theatrical troupe)
'walk in the auditorium' is the wordplay.
'walk' becomes 'troop' (troop can mean to walk or march around).
'in the auditorium' shows a homophone (sound like) (ie as heard on a stage).
'troop' is a homophone of 'TROUPE'.
(Other definitions for troupe that I've seen before include "Company of theatrical performers" , "Theatre company" , "travelling band" , "tour?" , "Company of dancers" .)