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

[Q]: Which composer was married to Clara Wieck from 1840 until his death in 1856?
[A]: clara schumann


[Q]: Which English comedian has joined Amanda Holden as one of the judges on the current series of 'Britain's Got Talent'?
[A]: britain's got talent


[Q]: Which German composer was assistant to Wagner at Bayreuth 1880-1, taught at Barcelona, Frankfurt and Berlin, and is best known for his opera Hansel and Gretel?
[A]:
composer