Stand-out performance? (4)
I believe the answer is:
solo
'stand-out performance?' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for solo that I've seen before include "Alone, unaccompanied" , "Type of whist" , "Fly aircraft" , "It's performed alone" , "Han - (Star Wars); fly unaccompanied" .)