TASK DEFINITION: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
PROBLEM: Who composed 'Eine Kleine Nachtmusik' in the 18th Century?

SOLUTION: eine kleine nachtmusik

PROBLEM: Aragon and Castile joined to form which country?

SOLUTION: aragon

PROBLEM: Who had a number one in 2000 with Black Coffee?

SOLUTION:
black coffee