Prolonged event, enthralling plays wanting a little new content (3-7)

'prolonged event' is the definition.
(event going on all night)

'enthralling plays wanting a little new content' is the wordplay.
I cannot really understand how this works, but
'a' is present in the answer.
'little' could be 'l' (abbreviation) and 'l' is located in the answer.
'new' could be 'n' (common abbreviation eg NT for New Testament) and 'n' is found in the answer.
The remaining letters 'lighter' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...