Thanks to the introduction of sound film around 1930,
the Accord-Harmonium can be seen in a short film excerpt from 1932 in a duet with a "Singing Saw".
The scene shows Berliners backyard musicians, whose business was progressively more difficult in this time of the growing spread of radio sets.
The Singing Saw involved will be today mostly regarded as a curiosity. However, The violin bow was and is guided along the saw blade by full musical aspirations up to participation in orchestras.
The Accord-Harmonium can be easily transported because the console can be removed from the undercarriage. What remains is the collapsible frame with air pipe and pedal bellows.
In the lower part of the attached console there is a magazine bellows which is designed to ensure uniform wind pressure regardless of pedal kicking.
The spiral springs visible on the left and right press n the bellows. (The red tin only keeps the view free.)
Air is supplied from the bellows (with recoil valves) via the air pipe which fills the magazine bellows through the seven holes.
The console lies on airtight and thus forms a large wind chest for all tongues.
On the right the piano mechanism, on the left for the basic basses and chords.
To illustrate the air supply, the back of the windchest is turned forward. In the hole of the windchest visible at the bottom left, the air pipe (top) plugged in.
On the reddish felts of the bass control mechanism lie in the assembled state the plungers of the knob keys.
By pressing on these, the wooden levers opened the desired valves, whereby the wind from the chest can escape via the reeds.
A piano lever (clavis) that has been removed.
At its rear end the valve is equipped with two leathers, which make the tone holes airtight close.
When the wind chest is folded up at the front end, its underside is as seen in the following image.
To the right, transvers the four zinc collection plates of the piano keyboard on two rows of flat chambers, the two 8' choirs.
Perpendicular to it, eight chord triads, each consisting of one reed on the right and two adjacent on the left collection plate. The chambers of the three chord reeds are connected and received via a tone hole Wind.
In the eight large wooden chambers on the left are the reeds of the basic basses.
According to the name Stark, the wind chest with reed plates and the control mechanism were delivered to the Glass company from Hugo Stark, the developer of the Chromatiphon.
On this instrument, built by the Menzenhauer company (private collection, Berlin), the playing aid (struts) has been preserved under which a sheet is placed.
The bass and chord keys on the left have tone letters and number from 1 to 8 (as the Griffschrift once did).
The functionality inherited from the accordion was advertised as "To be played by anyone at once" and was aimed at musical amateurs without knowledge of sheet music.
Harmoniums were replaced by electronic instruments from the 1960s onwards.
A metal strut is mechanismally connected to a piano key.
The top-to-bottom sheet following, it was also possible to press directly on the strut above a tone symbol (with displayed holding time).
Beside the symbols for the piano keyboard, the numerals for the accompanying bass and chord key are noted.
The various earlier mechanismal playing aids were continued in electronic programs, e.g. as automatic chord on electronic keyboards.
