Last performance with artist of the stars (6)
I believe the answer is:
astral
'of the stars' is the definition.
(I've seen this before)
'last performance with artist' is the wordplay.
'performance' indicates an anagram.
'with' is an insertion indicator.
'artist' becomes 'ra' (Royal Academician, member of Royal Academy of Arts).
'last' anagrammed gives 'astl'.
'astl' enclosing 'ra' is 'ASTRAL'.
(Other definitions for astral that I've seen before include "Related to the stars" , "To do with stars on altars" , "Characteristic of stars" , "like a star" , "Altars (anag)" .)