"Carmen” solo (4)
I believe the answer is:
aria
'carmen solo' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for aria that I've seen before include "Song, one from 'West Side Story' needing no introduction" , "Summertime perhaps" , "Operatic vocal" , "Song from an opera (4)" , "Musical performance" .)