The Aeolian 'Duo-Art' (upright piano) EXPRESSION BOX

              expression box

    It's hard to believe that something akin to The Ugly Duckling - hidden inside upright and grand pianos - could be the source of such exquisite expression, given special music rolls which challenge the system. This is where the dynamics for the THEME (solo - released via valves) and ACCOMPANIMENT (the rest of the keyboard intensities) are created ... either through perforations on the Duo-Art roll or via the Pianola levers next to the keyboard. Aeolian called the latter "The Duo-Art as a Pianola".

    On the lower left you see the Accordion Pneumatics, which "squeeze" and tug on the same levers which are available to the human roll interpreter. The accordion spacings are 1/16", 1/8", 1/4" and 1/2 inch (approximately Mezzo-Forte with only a few notes being played). These are additive, so are called 1, 2, 4 and 8, giving a range of 15 dynamic possibilities, for whatever activity and 'chord sizes' are being dictated by the music roll. (For example, an intensity of 5 = 4+1, a dynamic of 10 = 8+2 and a "crash" (sforzando) would be 8+4+2+1 holes on the tracker bar for the roll, or the THEME lever being moved to the fullest position.)

    The THEME and ACCOMPANIMENT are independent of each other, so have 15 levels each separated by the "solo accent" holes on the rolls and/or the levers for the Pianolist (roll interpreter).

    This is a simple idea carried out to extraordinary extremes. The vacuum from the pump is regulated by this unit, so the equalizers (above the accordions) move in accordance with the musical demands.

    Aeolian told its dealers in 1918 (and we have a copy of that text!) that "The Duo-Art as a Pianola" (meaning manually controlled) could outperform even their finest Pianola Pianos, which meant Weber and Steinway in those days. The lever controlled Duo-Art requires a musician and one who imparts his/her will upon the music. Once learned on an instinctive basis, the expression unit - with sliding knife valves - usually reacts more rapidly than the Accordion Pneumatics "pulling" on the same rods.

    Arrangements which take advantage of the solo effects, the "crash" valve (when the player is so equipped) and the levels of the THEME and ACCOMPANIMENT are usually memorable. They are not "reproductions" of a pianist at the keyboard as claimed by the piano companies, but a homage to hand playing and an artistic musical alternative in their own right. The Pianola levers give the user the opportunity to cut in or take over the automatic performance, as it's often necessary to 'fine tune' the arrangment to a particular piano.

    Patents were taken out by the Aeolian Co. around 1913, and the flow of instruments began in earnest nationally starting in 1916. From then on to the early 1930's, the Duo-Art had few rivals since this unique design stayed pretty much the same over the years. Cumbersome that this unit appears to the viewer,  it follows musical principles so continued to function as musical demands changed in the following decades. Today, in the 21st Century, people continue to enjoy Duo-Art players ... featuring a pneumatic wonder with moving rods, pneumatics and valves hidden inside ... and  this is the heart of the instrument.

--L. Douglas Henderson
ARTCRAFT Music Rolls
Wiscasset, Maine 04578