Piano roll

A piano roll is a music storage medium used to operate a player piano, piano player or reproducing piano. Piano rolls, like other music rolls, are continuous rolls of paper with holes punched into them. These perforations represent note control data. The roll moves over a reading system known as a tracker bar; the playing cycle for each musical note is triggered when a perforation crosses the bar.

Piano rolls have been in continuous production since at least 1896, and are still being manufactured today; QRS Music offers 45,000 titles with "new titles being added on a regular basis", although they are no longer mass-produced. MIDI files have generally supplanted piano rolls in storing and playing back performance data, accomplishing digitally and electronically what piano rolls do mechanically. MIDI editing software often features the ability to represent the music graphically as a piano roll, often with aids like a grid representing bars, beats, and other divisions, as well as shaded backgrounds representing the black and white keys of a piano.

The first paper rolls were used commercially by Welte & Sons in their orchestrions beginning in 1883.