A player piano is a type of mechanical piano. When you press the pedals, air is forced through holes in a roll of paper to press the keys and play a tune. A mechanically operated piano, especially a pedal-operated or motor-driven piano using pneumatic suction to move the keys in correspondence to the perforations on a turning piano roll. a piano that is played by machinery inside it. A long roll of paper with holes cut in it gradually turns and works the machinery, pressing down the keys on the piano to produce music = pianola. Piano that mechanically plays music encoded as perforations on a paper roll. An early version, patented in 1897 by the American engineer E.S. Votey, was a cabinet placed in front of an ordinary piano, with wooden "fingers" projecting over the keyboard. A paper roll with perforations corresponding to the notes passed over a tracker bar to activate the release of air by pneumatic devices that set the fingers in motion; the user could control tempo and loudness by levers and pedals. Soon this mechanism was built into the piano itself. The later "reproducing piano" could reproduce the nuances of tempo and dynamics in great performances, the roll having been produced by the performance itself. After the 1920s the phonograph led to the instrument's quick decline. Modern versions, such as the Yamaha Disklavier, are operated by digital memory on a computer disk