Piano roll

A piano roll is a music storage medium used to operate a player piano, piano player or reproducing piano. A piano roll is a continuous roll of paper with perforations (holes) punched into it. The perforations represent note control data. The roll moves over a reading system known as a 'tracker bar' and the playing cycle for each musical note is triggered when a perforation crosses the bar and is read.

The majority of piano rolls play on three distinct musical scales. The 65-note (with a playing range of A-1 to C#7) format was introduced in 1896 in the USA specifically for piano music. In 1900 a USA format playing all 88-notes of the standard piano scale was introduced. In 1902 a German 72-note scale (F-1, G-1 to E7) was introduced. All of these scales were subject to being operated by piano rolls of varying dimensions. The 1908 Buffalo Convention of US manufacturers standardized the US industry to the 88-note scale and fixed the physical dimensions for that scale.

Piano rolls were in continuous mass production from around 1896 to 2008, and are still available today, with QRS Music claiming to have 45,000 titles available with "new titles being added on a regular basis". Largely replacing piano rolls, which are no longer mass-produced today, MIDI files represent a modern way in which musical performance data can be stored. MIDI files accomplish digitally and electronically what piano rolls do mechanically. Software for editing a performance stored as MIDI data often has a feature to show the music in a piano roll representation.