Modern History/Schrammel accordion
A Schrammel accordion (German: Schrammelharmonika) is an accordion with a melody (right hand) keyboard in the chromatic B-Griff system and a twelve-button diatonic bass keyboard. It is named for a traditional combination of two Violins, Accordion and Contrabass known as Schrammelquartett, the music being performed was called Schrammel music, in the Vienna chamber music tradition.
In most cases, it has two or three sets of reeds tuned in unison configuration. The sound is quite different or special, when compared to modern chromatic button accordions. This is because it is much smaller and lighter than modern CBAs. The handmade reeds used may also contribute to its sound.