It requires a lot of extra work in the theatre (5,5)
I believe the answer is:
crowd scene
'work in the theatre' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'it requires a lot of extra' is the wordplay.
I cannot really see how this works, but
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is located in the answer.
'lot' could be 'd' and 'd' is found in the answer.
'of' could be 'o' and 'o' is located in the answer.
'extra' could be 'w' (abbreviation for 'wide' - cricket) and 'w' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?