Ceremony is just for the audience (4)
I believe the answer is:
rite
'ceremony' is the definition.
(I know that rite is a type of religious ceremony)
'just for the audience' is the wordplay.
'just' becomes 'right' (similar in meaning).
'for the audience' indicates a 'sounds like' (homophone) clue (how an audience might hear it).
'right' sounds like 'RITE'.
'is' acts as a link.
(Other definitions for rite that I've seen before include "(Words for) ceremony" , "Religious ritual" , "form of service" , "Solemn ceremony" , "Ceremonial procedure" .)