Group of stars performing around city (5)
I believe the answer is:
orion
'group of stars' is the definition.
(I know that Orion is a constellation)
'performing around city' is the wordplay.
'performing' becomes 'on' (as in being on stage).
'around' is an insertion indicator.
'city' becomes 'Rio' (Rio de Janeiro).
'on' enclosing 'rio' is 'ORION'.
(Other definitions for orion that I've seen before include "Great hunter of Greek legend and a constellation" , "Constellation in the form of a belt" , "Rigel constellation" , "Star" , "One who would hunt" .)