All round, it's just the house for a bit of opera (4)
I believe the answer is:
hoop
'all round' is the definition.
'hoop' can be an answer for 'round' (thesaurus). I'm not certain of the 'all' bit.
'just the house for a bit of opera' is the wordplay.
I cannot really see how this works, but
'house' could be 'ho' (abbreviation for house) and 'ho' is found within the answer.
'bit' could be 'o' (resembles 0, a binary digit or bit) and 'o' is located in the answer.
A single letter 'p' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
'it's' acts as a link.
Can you help me to learn more?
(Other definitions for hoop that I've seen before include "Circlet" , "children's toy" , "Rigid circular band" , "Croquet target" , "Circle, ring" .)