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: Who was the only boxer to win a world title without ever having a manager?

Answer: boxing


Question: Aaron Copeland wrote a ballet about which American folk hero?

Answer: aaron copeland


Question: Who composed the opera Dido and Aeneas which was the first performed in London in 1689?

Answer:
dido and aeneas