The piano roll was the first medium which could be produced and copied industrially and made it possible to provide the customer fast and easy with actual music.
A piano roll is a roll of paper with perforations (holes) punched in it. 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 first had 58 holes, was expanded to 65 and then was upgraded to 88 holes (generally, one for each piano key). When a perforation passes over the hole, the note sounds.
Piano rolls have been in continuous mass production since around 1896. Though they are still being made 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.
The first paper rolls were used by Welte & Sons in their Orchestrions since 1883. After hundreds of companies of this booming business produced piano rolls different in size and perforation, in 1909 the American producers of piano rolls and mechanical pianos as well agreed to a standard in the Buffalo Convention.
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 1904 by the Welte company in Germany with their reproducing piano Welte-Mignon, who recorded such famous pianists as Camille Saint-Saëns, Richard Strauss, Alexander Scriabin and George Gershwin. The Welte company made an invaluable historical record of the playing of famous performers who did not make sound recordings. In around 1911 hand played rolls for reproducing pianos started production in the USA, and have provided certain types of hand played recordings which can also play back the dynamics as performed by the pianist. Actually, for example the Welte-Mignon could only play two different velocities at a time, (lower and higher part of the keyboard, with the border between those two freely movable), but there were certain tricks like playing a note a minute amount earlier to give it its own velocity.
However, since rolls for the pianola were not generally recorded by hand, there is also the possibility to create music that is impossible for humans to play, or, more correctly, music that was not conceived in terms of performance by hand, whether inhumanly complex or not. Over one hundred composers wrote music specially for the player piano during the course of the 20th century, notably Conlon Nancarrow, Igor Stravinsky, Alfredo Casella and Paul Hindemith.
The Duo-Art, Ampico and Welte-Mignon 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 capable pianos.
Duo-Art featured artists such as Ignace Jan Paderewski, George Gershwin,Maurice Ravel, Percy Grainger, Leopold Godowsky and Ferruccio Busoni. The Ampico brand's featured artists included Sergei Rachmaninoff, Leo Ornstein, and Marguerite Volavy. For Welte-Mignon there played artists like Gustav Mahler, Claude Debussy, Alexander Scriabin
There were hundreds of companies worldwide producing rolls during the peak period of their popularity (1900–1927). Some other non-reproducing rolls makers of live performances are listed below together with their most memorable recording artistes.
Rolls for the reproducing piano were generally made from the recorded performances of famous musicians. Typically, a pianist would sit at a specially designed recording piano, and the pitch and duration of any notes played would be either marked or perforated on a blank roll, together with the duration of the sustaining and soft pedal.
Reproducing pianos can also re-create the dynamics of a pianist's performance by means of specially encoded control perforations placed towards the edges of a music roll, but this coding was never recorded automatically. Different companies had different ways of notating dynamics, some technically advanced (though not necessarily more effective), some secret, and some dependent entirely on a recording producer's handwritten notes, but in all cases these dynamic hieroglyphics had to be skillfully converted into the specialized perforated codes needed by the different types of instrument.
Recorded rolls play at a specific, marked speed, where for example, 70 signifies 7 feet of paper travel in one minute, at the start of the roll. On all pneumatic player pianos, the paper is pulled on to a take-up spool, and as more paper winds on, so the effective diameter of the spool increases, and with it the paper speed. Player piano engineers were well aware of this, as can be seen from many patents of the time, but since reproducing piano recordings were generally made with a similar take-up spool drive, the tempo of the recorded performance is faithfully reproduced, despite the gradually increasing paper speed.
The playing of many pianists and composers is preserved on reproducing piano roll. Gustav Mahler, Edvard Grieg, Claude Debussy, Scott Joplin, Sergei Rachmaninoff, Alexander Nikolayevich Scriabin and George Gershwin are amongst the composers who have had their performances recorded in this way.