On the contrary, had seen it amused constituents taking in early performance (7)
I believe the answer is:
matinee
'early performance' is the definition.
(I've seen this in another clue)
'on the contrary had seen it amused constituents' is the wordplay.
'on the contrary' says the letters should be written in reverse (letters in the opposite or contrary direction).
'constituents' says the answer is hidden in the clue (I've seen 'constituent' mean this).
'eenitam' can be found hidden inside 'had seen it amused'.
'eenitam' reversed gives 'MATINEE'.
'taking in' is the link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for matinee that I've seen before include "Afternoon performance (of play etc)" , "Daytime performance of play etc" , "in which players may appear?" , "Afternoon theatre" , "early "performance"" .)