In contrast to the previous accordion from Italy, the manual is now at the front, which results in a new direction of movement of the keys towards the chord mechanism.

The control shafts can now be turned by sliders instead levers, which makes for a more robust construction. The two inner rows of keys on the left belong to the single basses, the others to the chords.

The slanted rows ascending from the inside to the outside each belong to a keynote, which is located in the second row. Neighbouring slanted rows are in fifths, so that three rows on top of each other form a main cadence.

Left in the picture 12 vertical control shafts of the low-tuned single basses, whose deckers are under the shafts.

On the right in the picture 12 control shafts of the 12 single tones for the chord formation. The lugs punched out on the horizontal sliders turn the control shafts of a desired chord and the corresponding valves are lifted.

Within the space of 100 years, a multitude of inventions have turned Demian's accordion with 5 keys and 10 bisonoric chords to a chord machine with a range of chords that can be selected at will.

The sliders with punched-out lugs are stacked in pairs. If the front, lower slider is moved to the right, it turns 3 waves over its 3 lugs, which lift 3 valves for this chord.

The front, upper slider creates with 4 lugs the same chord plus an additional tone. The result is a fourtone sound (valves under the waves).

With 12 reeds (usually c1-b1), the instruments can be equipped with any chords. But by doing so, the range of the chords is limited to a major seventh, so that they often resound in inversions.

The (single) basic basses are also within the range of a major seventh (C to B). Upwards are broken down to C when B is reached. Small-octave single tones are not present on the standard bass.

Often the notated single bass notes are then replaced by suitable chords, which changes the character of a piece and can rob it of its charm.

These restrictions imposed by the instrument can lead to a simplistic, chord-heavy style of playing, which must be seen as a consequence of the mechanised principle of action.

The aim of the development of the accordion through to the standard bass as a semi-automatic chord machine was to create an instrument that was easier to play in order to ultimately increase the number of buyers.

But the boundaries of the given harmony corset can also be shifted by combining chord keys, which accordionists such as Richard Galliano, Frank Marocco, Hubert Deuringer and others prove.

In order to make the performance more colourful, stops are often used, i.e. variable choir combinations. Stops (also with indicators, see picture) can enrich the sound.

The decision in favour of an accordion with a standard bass depends on the musical styles and pieces that one mainly want to play.

The accordion achieves its greatest effect in the musical styles it has shaped:

Musette, Cajun/Zydeco, Tex-Mex, Vallenato (cumbia), as well as European folk music. In these, it is indispensable.

In other areas, especially classical music, the musical limitations mentioned above were of the standard bass has given rise to many developments that have led to its dissolution into single tones with a wider range of tones. All this in order to provide the left hand with options such as piano and bandonion.

The ready chords, the essence of the accordion, as well as the limited bass notes were seen as an obstacle to playing.