Inscription on the instrument:

"Heinrich Suhr, Neuenrade/W., Musik-Instr.Fabrik, Deutschland"

Around the middle of the 19th century, two types of construction developed in Vienna: with an open or covered mechanism.

According to their later production centres, these probably were called the Viennese and German models respectively (Graf, p. 61). The accordion illustrated corresponds to the German model (Deutsche Bauform) with exposed valves and clavis (levers) and is unisonoric on the melody side.

On the left side, too, the valves are mounted on the outside of the handle, which was not possible otherwise, because this is divided into four chambers on the inside and acts as a resonance box to amplify the bass tones.

The two lower levers operate four keynotes, the two upper ones four fourtones. They are therefore assigned bisonoric.

On the inside, the four chambers in the handle are closed by reed plates.

The two lower chambers are each by a large and a small reedplate, because the keynote sounds in two voices. The small reedplates each carry the 8' reed, the large ones the 16' reed tuned an octave lower.

The visible reeds sound when the lever is actuated by pressure wind (push the bellows) and the reeds covered by the valve leather when the wind is sucked in.

The upper chamber leads to these reed plates of the chord tones, each consisting of four tones, whose reeds are riveted on. The chords sound in one choir.

The multiple tones of a collector plate are played with a hand lever (overleaf), either with pressure or suction wind.

The leather prevent wind from escaping via the mute reeds, which would have to be compensated by the player by additional bellows movement. The visible reeds are also covered with movable leather on the back.

The melody side is 3-choirs (8'+8°+4'). The choirs are individually selectable via six draw stop (the buttons at the top).

For this purpose, a slider (wooden strip) is moved vertically via the upper buttons so that its holes are in front of the chamber and the reeds receive wind. The stops must be drawn in pairs for both rows of keys so that all notes sound with the same number of choruses. All stops pulled out produce the full 3-choirs sound.

For holding the instrument there is a thumb loop on the back of the handle, shoulder straps were not yet in use.

Right side inside (shortened picture)

By means of two drawn stops (one each row of keys) the 8' choir is switched on. The slider ends of the registers that are not activated protrude below. The leftmost stop is also half-pulled for demonstration purposes to show the slider behind the tone holes of two removed reedplates.

Today's accordions are also registered according to this principle. However with toggle switches, metal mechanics and plastic slider. Stops by means of slider originates from organ building, where already longer a dynamic sound has been attempted by switching choirs of pipes on and off.

The right side has a tremulant, which is switched off in the picture with the top button, so that the wind unhindered through the flap opened by thread.

When the tremolo button is pressed down, the flap is closed due to lead weights and is periodically opened by the pressure wind. For suction wind, there is behind the other opening, a second tremolo valve.

(Detailed see with Tremulant)

"Association of Friends of Music Staßfurt 1908"

Above an enlarged section with three accordions.

Various accordions in German design in a sales catalogue from around 1870.