Male interrupting individual mid-performance? (7)

I believe the answer is:
onstage
'mid-performance?' is the definition.
I can't judge whether this definition defines the answer.
'male interrupting individual' is the wordplay.
'male' becomes 'stag' (a stag is a male deer).
'interrupting' means one lot of letters goes inside another.
'individual' becomes 'one' (an individual is one person).
'stag' placed inside 'one' is 'ONSTAGE'.
Can you help me to learn more?
(Other definitions for onstage that I've seen before include "Visible to (theatre) audience" , "as a player may be?" , "Acting" , "in full view of the audience" , "In view of house" .)
