Together — performing live (2,7)
I believe the answer is:
in concert
I believe this clue is a double definition.
'together' is the first definition.
(I know that together can be written as in concert)
'performing live' is the second definition.
(I've seen this before)
(Other definitions for in concert that I've seen before include "Showing teamwork" , "All together - at a musical entertainment?" , "All together, in combination - while performing?" , "Working together" , "Acting jointly" .)