Wildly exaggerated, as a performance (4,3,3)
I believe the answer is:
over the top
'wildly exaggerated as a performance' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for over the top that I've seen before include "How infantry used to go into action" , "Stallone film" , "Where the circus flag might be" , "Too [B?]old" , "To an exaggerated degree" .)