Beethoven wrote a sets of variations for violoncello and piano for two numbers from the opera.
From the en.wikipedia.org
More examples
Cello: a large stringed instrument; seated player holds it upright while playing
The cello (pronounced ; plural cellos or celli) is a bowed string instrument. The word derives from the Italian violoncello. A person who plays a cello is called a cellist. The cello is used as a solo instrument, in chamber music, and as a member of the string section of an orchestra. ...
A large stringed instrument of the violin family, but smaller than the double bass