The pianola (pronounce: "pee-ah-NO-la"), also called the player piano, is a piano which has a pneumatic mechanism so that it can play by itself. The air for this system came from a pump operated by the players feet, and in some later models, an electric pump. Inside the piano are paper rolls which have holes punched in. These holes release air which in turn triggers the keys to play. When the pianola plays itself the keys of the piano can be seen "playing themselves".