an acoustic piano where the sound is produced by moving the keys, which in turn cause the hammers to strike the piano strings

an automated musical instrument that produces music by vacuum pressure using a punched paper roll

a real piano with the addition of the player action and related machinery which (in my opinion) amounts to the mechanics of an automobile within the piano case

a type of piano which plays

A piano with mechanism that causes the keys to play. Player pianos operate by the use of a perforated paper roll and a pneumatic system.

The player piano is a type of piano that plays music automatically without the need for a human pianist. Instead, the keys are struck by mechanical, pneumatic or electrical means. The player piano was most popular in the first half of the 20th century, roughly at the same time as the acoustic phonograph.

Player Piano, author Kurt Vonnegut's first novel, was published in 1952. The dystopian story takes place in a near-future society that is almost totally mechanized and automated, eliminating the need for human laborers. This widespread mechanization creates conflict between the wealthy upper class—the engineers and managers who keep society running—and the lower class, whose skills and purpose in society have been replaced by machines.