Performing with a trio, touring province (7)
I believe the answer is:
ontario
'province' is the definition.
(province of Canada)
'performing with a trio touring' is the wordplay.
'performing' becomes 'on' (as in being on stage).
'with' is a charade indicator (letters next to each other).
'touring' is an insertion indicator (touring can mean going round).
'a' placed within 'trio' is 'tario'.
'on'+'tario'='ONTARIO'
(Other definitions for ontario that I've seen before include "One of the Great Lakes" , "Smallest of the Great Lakes" , "part of Canada" , "Most easterly Great Lake" , "provincial area" .)