Leonardo da Vinci invented the viola organista, a keyboard instrument combining ideas from bowed strings and keyboard mechanisms.
Leonardo’s drawings for the viola organista show a keyboard controlling strings that were sounded by rotating wheels or continuous friction surfaces. Pressing a key would bring a string into contact with the moving mechanism, allowing the player to produce sustained tones in a way that resembled a bowed violin or viola.
The instrument was never completed by Leonardo and did not become a standard Renaissance instrument. Its concept differs from a piano, in which hammers strike strings, and from a hurdy-gurdy, in which a hand-turned wheel continuously bows strings while keys select notes.
The surviving drawings demonstrate Leonardo’s interest in solving musical problems mechanically. Several modern builders have constructed versions based on his plans, but these reconstructions involve interpretation because the notebooks do not provide every detail needed for a definitive original build.