Leonardo da Vinci designed the viola organista, an instrument that used a bow to create continuous sound from strings.
The concept appears in Leonardo’s notebooks and combines features of a keyboard instrument with those of bowed string instruments. Pressing keys selected strings, while a rotating wheel or belt rubbed against them to produce sound. This allowed the player to control pitches from a keyboard while obtaining a sustained, bowed tone.
Leonardo made several related sketches, and the surviving drawings show that he was exploring the mechanism rather than presenting one finalized commercial instrument. The viola organista is therefore associated with Leonardo’s invention studies, but it was not a standard Renaissance instrument played by him in a documented public performance.
Modern builders have constructed working versions from the notebook designs. The instrument is sometimes confused with a hurdy-gurdy, but a hurdy-gurdy normally uses a hand-turned wheel and keys, whereas Leonardo’s proposal was specifically linked to a keyboard and a continuously moving bowing mechanism.