The Schrammel Accordion
This accordion is used in Viennese chamber music and klezmer, which has the treble buttonboard of a chromatic button accordion and a bisonoric bass buttonboard, similar to an expanded diatonic button accordion.
Accordions Accordion Types
Unisonoric
The height of the tone is independent of the bellows movement direction.
Bisonoric
The height of the tone depends on the bellows movement direction.
Chromatic
Chromatic accordions are based on twelve half tones of the tempered scale.
Diatonic
Diatonic button accordions use a button keyboard, limited by the diatonic scale (no half-tone intervals between the notes).
Piano Keyboard
Piano keyboard accordions are chromatic. The maximum number of keys is forty-five, which is enough to play even sophisticated concert pieces. Piano accordions can have three, four, or even five voices, creating multi-timbre sound. The register switches allow to automatically double the sounds in octave and in unison, thus changing the timbre. Another distinctive feature of the piano accordion is that it can be played only with two well-fitting shoulder straps, the correct strap adjustment being the key thing here.
Button Keyboard
Button accordions can be chromatic and diatonic alike. The Russian bayan, for example, is a type of a chromatic button accordion. Bayans have three- or five-row right-hand manual. In a five-row keyboard the first two rows (from the bellows) are auxiliary, duplicating the notes form the other three rows. Bayans can have three, four, or five voices, depending on the maximum number of reeds that sound simultaneously when you press one button on the right-hand manual.
Left-hand Manual
A typical left-hand manual consists of one hundred and twenty buttons. It can be equipped with a pre-set, variable, or pre-set-variable accompaniment.
Many hybrid accordion models, combining various button layouts and features appeared in the course of music history. Most of them are merely rare artifacts acting as exhibits; only a small fraction of them are really in use:
The Schwyzerorgeli Accordion
This type is also called the Swiss organ, which usually has a three-row diatonic treble and eighteen unisonoric bass buttons in a bass/chord arrangement — actually a subset of the Stradella system in reverse order like the Belgian bass – that travel parallel to the bellows motion.
The Trikitixa Accordion
This is the national musical instrument of the Basque people that has a two-row diatonic, bisonoric treble and a twelve-button diatonic unisonoric bass.
The British Chromatic Accordion
This type is the favoured diatonic accordion in Scotland. While the right hand is bisonoric, the left hand follows the Stradella system. The elite form of this instrument is generally considered to be the German manufactured Shand Morino, produced by Hohner with the input of Sir Jimmy Shand.