need a more appropriate picture!
What are they?
These were the luxury models aimed at the more affluent classes and were the top-end “hi-fi” systems of the player piano era; they were much more sophisticated than the straightforward foot-pumped player pianos and came with a price tag to match. There were various systems e.g. Duo-Art, Ampico, Welte (of which there were three variants) and various other less common ones (e.g.Artrio-Angelus, Triphonola). They play specially-adapted rolls which are recordings of actual performances of pianists, and include special coding in the margins of the rolls to play the music with all the loud-and-soft expression. Many famous pianists (including Rachmaninov, Paderewski and Rubinstein) recorded reproducing piano rolls, mostly during the period 1905-1930. The quality of gramophone recordings only reached an acceptable standard in the mid/late 1920’s and until then often involved serious distortions to the playing style to get a usable recording, so these piano roll recordings are often a more faithful likeness of early 20th century pianists’ playing than their sound recordings.
How do they work?
The basic method of playing the notes is identical to that of the straightforward player piano as explained elsewhere on the website. They are still operated by air, under the control of a paper roll, but the air is pumped either by a set of electrically-driven bellows or by a “Motora” high-speed rotary pump. Variations in tempo, pauses, breaking of chords etc. are all contained in the note perforations of the rolls, which directly contain the keystrokes of the pianist, while additional perforations in the margins of the roll (typically using tracks borrowed from the top and bottom few notes) contain special coding which controls the dynamics (loud and soft expression) by varying the level of suction applied to the player mechanism, along with control of the piano’s sustain (loud) and half-blow (soft) pedal. This diagram shows the basic layout of a typical reproducing piano.
However, the methods by which the dynamic perforations are converted into different levels of suction vary drastically from manufacturer to manufacturer. In the UK, the Duo-Art system is the most common, the Ampico Model A system less common, Welte systems are unusual and other systems (Ampico B and others) are relatively rare. The following brief descriptions are reinforced with simple frame-by-frame descriptions and animations.
The Duo-Art system uses two suction regulators, one to control the background (accompaniment) level of playing, the other to control louder notes (the theme) playing above the background level. By default, both the treble and bass halves of the player mechanism (“the stack”) are controlled by the accompaniment regulator, but this level of playing is over-ridden by the theme regulator when additional perforations (known as solo or accenting perforations) appear. Here is a feature-by-feature description of how the Duo-Art system operates. A short video shows how the build-up of expression levels, and the changeover from accompaniment to theme levels.
The Ampico Model A system also uses two suction regulators but these are largely independent and each one is connected to half of the player mechanism (“the stack”) as in the diagram near the start of the present section. There are two main aspects to the Ampico expression system: three levels of intensity which can be activated in different combinations to give seven levels of loudness, and a crescendo system which is superimposed onto the intensity levels to give an underlying slow or fast increase or decrease in playing level. Additional levels of expression are provided using a pump spill mechanism known as the amplifier, but that aspect is not covered here. Here is a feature-by-feature description of how the Ampico Model A system operates.