In this task, you're given an open-domain question. Your task is to provide an answer to the given question. There is only one unique answer for each question. Your answer should be short, and refer to an entity, date, number, etc. Do not put your answer in the context of a sentence.

Who played the music for eddie and the cruisers?
John Cafferty & The Beaver Brown Band

Who wrote the song flight of the bumblebee?
Nikolai Rimsky-Korsakov

Which unit is used to measure mass in the metric system?

kilogramme