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a piano with an installed or attached device for playing without a pianist. Mechanical pianos included the phonola, the Welte-Mignon, and the pianola.
In mechanical pianos dating from the end of the 19th and beginning of the 20th century, the keys, which are controlled by perforated paper rolls (mechanical note rolls), are set in action by a complex pneumatic system with a pedal or electrical driving gear. The use of perforated rolls was a novel means of transcribing the notes of a musical piece. Almost all mechanical pianos can be played like a regular piano. With the spread of the phonograph and tape recorder, mechanical pianos fell into disuse.