Left side: C - b1 (chromatic)

Turn six into five: A significant change is the elimination of the outermost of the 2 auxiliary rows, which only leads to handle changes in row 4. The reduction to 5 rows significantly reduces the design effort for the internal keyboard mechanism.

In addition, the key manual has been rotated slightly from the vertical (with the pivot point at the bottom) to allow better ergonomic access to chromatic tone sequences.

An option would be the previously customary left-hand grip with thumb hole (left, wood-coloured) for a freer vertical movement of the hand not only with short fingers.

Left manual: The outermost auxiliary row G#1 - g#1 is omitted. There remain 5 rows with notes at intervals of a major third.

There is a minor third or semitone step between neighbouring rows. The manual can be played chromatically throughout via the latter.

The auxiliary row 5 (blue) repeats row 1.

All major/minor triads and his inversions can be played with the same fingering, as can all seventh chords of the notes in row 1 to 3. The septime chords of the 3 tones in row 4 have a different, but again constant fingering.

Chord progressions a.s.o. can be played in all keys with the same fingering with only a few exceptions in row 4.

Mechanism left side

On the left, the extremely complex sheet metal bending work that used to be required to connect the levers and key buttons. A test of nerve for every bandonion maker.

On the right the significantly minimised bending effort through the use of a regulator mechanism that corresponds to the principle of the Reformklaviatur developed by Hugo Stark at the beginning of the 20th century.

Mechanism right side

On the Reformklaviatur, the deckers are not attached to the key levers, but are located on a short rocker arm underneath them. When pressed, the key lever presses on the rocker lever of the valve with a small pusher attached to its underside and lifts it (opens it).

With this construction, many key levers for a large number of keys can be arranged close together without interference and with ease of manufacture. The closing noise of the valves is also minimised.

Right manual:

At the suggestion of Bernd Machus, the notes of the Gerlinger auxiliary row (orange) were chosen a semitone higher so that they repeat the fourth note of the rows (previously it was the third).

Example for a chromatic tone sequence: g > g# > a with the first 3 fingers > index finger to the auxiliary row for tone 4 a# > ring finger b > the little c1.

The spread is achieved between the index and ring fingers, which is easyer than with the middle finger.

Thanks to the repeat row (blue), the legato can be continued as desired...

As the rows are spaced in fifths, fifths are played with one finger simultaneously on two keys, which makes it possible to play up to six-part chords.

Mechanism right side

Here, too, on the left, the previously complex sheet metal bending process.

Peter Spende avoids this by aligning the levers at a graduated angle.

Mechanism right side by Peter Spende

Julius Zademack also knew how to help himself around 1909 with levers mounted at an angle.

There is no doubt that the design of such a regulator requires a great deal of effort and craftsmanship. Once completed, however, it enables a much more efficient production process than the constantly laborious sheet metal bending of the earlier Kusserows instruments.

Manufacturers sign:

PS Premíer Bandoneon Manufaktur
Peter Spende

Thanks to the craftsmanship and design innovations of Peter Spende, initially in collaboration with Klaus Gutjahr, and the practical suggestions of musician Bernd Machus, the Kusserow was developed into a new quality after decades of slumber.

Unfortunately, only a few such instruments have been built, because Peter Spende returned to his old profession.

Unfortunately, there are no more construction documents available. These would have to be recreated after a Spende instrument and made generally available.

A great advantage of the Kusserow is its continuous chromaticism over neighbouring keys on both sides like on the piano, interrupted only by the edges of the manual.

Without exaggeration, it can be regarded as one of the most practicable bandonion types thanks to its strictly logical and player-friendly keyboard system. The problem is the lack of available instruments for those interested. For children from the age of 2, a reduced, simple concertina would also be very welcome.

Bandonion friends, or those who want to become bandonion friends and would like to help with the points mentioned, are very welcome: post@bandonioninfo.de

Playing instructions by Bernd Machus on youtube.com