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 or clarinet, and contraguitar known as a Schrammelquartet – a group that played Schrammelmusik in the Vienna chamber music tradition. In most cases, the instrument has two or three sets of reeds tuned in unison configuration. Its sound is quite different from modern chromatic button accordions, because it is much smaller and lighter.