"Swan Lake" composer (11)
I believe the answer is:
tchaikovsky
'swan lake composer' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for tchaikovsky that I've seen before include "'Swan Lake' composer" , "Sleeping Beauty ballet composer" , "Russian scorer" , "Pyotr -, Russian composer" , "Peter ---, Russian composer" .)