Stage musical welcomes international actor (7)
I believe the answer is:
olivier
'actor' is the definition.
(Sir Laurence Olivier)
'stage musical welcomes international' is the wordplay.
'stage musical' becomes 'oliver' (musical based on Oliver Twist).
'welcomes' is an insertion indicator (in sense of 'invites in').
'international' becomes 'i' (abbreviation eg in IMF).
'oliver' going around 'i' is 'OLIVIER'.
(Other definitions for olivier that I've seen before include "First actor to become a life peer" , "Sir Laurence -, English actor (Hamlet, nineteen fourty eight)" , "- Messiaen, Twentieth century French composer" , "Laurence (Lord) ---, actor" , "Great player" .)