Steirische Harmonika
The Steirische Harmonika (Austrian German pronunciation: [ˈʃtaɪrɪʃɛ harˈmoːnika]) is a type of bisonoric diatonic button accordion important to the alpine folk music of Croatia (Hrvatsko zagorje), Slovenia, the Czech Republic, Austria, the German state of Bavaria, and the Italian South Tyrol. The Steirische Harmonika is distinguished from other diatonic button accordions by its typically richer bass notes, and by the presence of one key per scale row that has the same tone on both compression and expansion of the bellows, called a Gleichton.