In 1904 in southern Germany, Edwin Welte invented a device for reproducing the performances of famous pianists with a more lifelike rendering than was possible with the acoustic recording method of the day. He called it the Mignon (French for dainty) to distinguish it from the much larger organs and orchestrations previously made by the Welte Company. By 1913, several other firms had built reproducing pianos with varying degrees of success and much competition. Two other versions of the Welte-Mignon were built, one by Welte’s brother-in-law Karl Bokisch in Germany and the other under license in the U.S. The American Piano Company brought out the re-enacting piano which they called the Ampico, and the Aeolian Company of London and New York introduced their Duo-Art Pianola Piano.
Reproducing pianos work on the pneumatic principle, in the same way as ordinary player pianos, but they differ in three important respects. The motive power is supplied by an electric motor, and re-rolling is automatic. All expression devices, for subduing and accentuating as well as the pedals, are operated by marginal perforations on the roll; and the paper speed is set at the start and kept constant.
Tempo changes and musical phrasing are obtained by differences in the length of the note perforations. The Duo-Art machine will play any 88-note roll as well as the Duo-Art rolls; some models are fitted with both pedals and electric motors. When changing between types of rolls a switching arrangement is operated which cuts out the extreme four bass and treble notes. The eight positions in the tracker bar thus vacated are used to control expression. Those on the left control the accompaniment and those on the right control melody line. Using a series of graded pneumatics (ratios 1:2:4:8) singly or in combination, it is possible to obtain sixteen degrees of touch. The accompaniment regulator controls the whole piano all the time, while the melody regulator accentuates any bass or treble notes as required. The touch of the concert pianist is thus reproduced more accurately than on the ordinary player piano.
The popularity of the player piano began to die out in the late 1920s because of competition from broadcasting and from new methods of recording and playing gramophone records. In the meantime, however, such popular piano players as Fats Waller and George Gershwin made piano rolls which are still sought after by collectors and re-issued on records, and famous pianists such as Josef Hofmann and Jan Paderewsky, as well as the composers Gustav Mahler and Claude Debussy, recorded their styles on the reproducing pianos.