Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.

[Q]: 'Highway 61 Revisited' and 'Blood On The Tracks' were both albums released by which popular singer?
[A]: highway 61 revisited


[Q]: Billy the Kid was a native of which US state?
[A]: billy


[Q]: The Lilac Fairy and Carabosse are two conflicting forces in which Tchaikovsky ballet?
[A]:
ballet