A piano roll is the media used to operate the player piano or pianola.
Piano rolls are a roll of paper with perforations (holes) punched in them. The position and length of the perforation determines the note played on the piano. The piano roll moves over a device known as the 'tracker bar', which has 88 holes (one for each piano key). When a perforation passes over the hole, the note sounds.
Piano rolls started mass production around 1897, and are still being made today. There are two main types of piano rolls - 'hand played' and 'arranged'.
'Arranged' rolls are produced simply by cutting holes in the paper with a knife and ruler, using the sheet music or other arrangement as a guide. This results in somewhat mechanical sounding rolls.
'Hand played' rolls are made using some form of recording device that marks the paper as a pianist plays. The marked paper is then used as a guide when the holes are cut. Extra notes may be added and errors deleted after the recording process. This method was in use as early as 1903 by the Welte company in Germany, who recorded such famous pianists as Camille Saint-SaŽns and Richard Strauss. In around 1911 hand played rolls started production in the USA, and have provided an invaluable historical record of the playing of famous performers who did not make sound recordings. Certain types of hand played recordings can also play back the dynamics as performed by the pianist.
There were dozens of companies producing rolls during the peak period of their popularity (1900-1927). Some of the larger companies are listed below, with their most promiment recording artsts.
QRS Company - Max Kortlander, Pete Wendling, J. Lawrence Cook, and Victor Arden
Imperial - Charley Straight, Roy Bargey
Vocalstyle - Jelly Roll Morton, Mary Allison, Walter Davison
The Duo-Art and Ampico brands were known as 'reproducing' piano rolls, as they could accurately reproduce the touch and dynamics of the artist as well as the notes struck, when played back on Duo-Art and Ampico capable pianos.