The accordion is one of several European inventions of the early 19th century that used free reeds driven by bellows. The instrument called accordion was first patented in 1829 by Cyrill Demian, a man of Armenian descent, in Vienna.
Demian’s instrument bore little resemblance to modern instruments. It only had a left hand buttonboard, with the right hand simply operating the bellows. One key feature for which Demian sought the patent was the sounding of an entire chord by depressing one key. His instrument also could sound two different chords with the same key; one for each bellows direction (a bisonoric action).