Prince of opera (4)
I believe the answer is:
igor
'prince of opera' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for igor that I've seen before include "Stravinsky, for example" , "-- Stravinsky, composer" , "Prince in Borodin's opera" , "Stravinsky's first name" , "Hero of Borodin" .)