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

[Q]: Which Union leader of the American Civil War gave his name to a tree in California's 'Sequoia National Park'?
[A]: american civil war

[Q]: What is the county town of Derbyshire?
[A]: derbyshire

[Q]: Which great composer, composed so many songs between 1815 and 1828 that the Oxford Dictionary of Music doesn't attempt to list them all?
[A]:
composer