accordion

Musical instrument of the free-reed organ type, comprising left and right wind chests connected by flexible, pleated bellows. The accordionist's right hand plays the melody on a piano-style keyboard of 26-34 keys, while the left hand has a system of push buttons for selecting single notes or chord harmonies.

It was patented under the name of Handäoline by Friedrich Buschmann in Berlin, Germany, in 1822, and by Cyrill Damien under the name Akkordion (German ‘harmony’) in Vienna, Austria, in 1829. The accordion spread throughout the world and can be heard in the popular music of Germany, France, China, Russia, and the USA.