Song for a coloratura (4)
I believe the answer is:
aria
'song for a coloratura' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for aria that I've seen before include "Operatic number" , "Song, one from 'West Side Story' needing no introduction" , "Piece of music" , "Operatic air" , "Operatic solo, duet, etc" .)