Being there, have a ball a couple of hours before midnight? (10)
I believe the answer is:
attendance
'being there' is the definition.
(to attend something is to be at it)
'a ball a couple of hours before midnight?' is the wordplay.
I cannot really see how this works, but
'a' could be 'an' and 'an' is found in the answer.
'before' could be 'e' (I've seen this in other clues) and 'e' is found in the answer.
This explanation may well be incorrect...
'have' acts as a link.
Can you help me to learn more?
(Other definitions for attendance that I've seen before include "how many are watching?" , "Act of being present" , "Service" , "all that turned up" , "Number present" .)