Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
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Question: Which singer played Billie Holiday in the 1972 film 'Lady Sings The Blues'?

Answer: lady sings the blues

Question: What famous song from the film Butch Cassidy and the Sundance Kid won an Oscar for best song?

Answer: academy award for best original song

Question: In the novel '20,000 Leagues Under The Sea' what was the name of the captain of the submarine Nautilus?

Answer:
twenty thousand leagues under the sea