Leonardo da Vinci designed the viola organista, a keyboard instrument combining features of bowed strings and an organ.
The instrument used a keyboard to control rotating wheels or belts that rubbed against strings, producing sound in a way related to a bow moving across a string. Leonardo developed several versions in drawings from the late fifteenth and early sixteenth centuries. The player could press keys while the mechanism continuously supplied the friction needed to sound the strings.
The viola organista was never built by Leonardo in a known surviving form, and the exact details varied between his sketches. It is therefore not simply a violin with keys, nor is it a conventional pipe organ. Modern instrument makers have constructed working interpretations based on Leonardo’s drawings. The invention demonstrates his interest in solving musical problems mechanically, especially the challenge of sustaining string sounds while allowing a single performer to control many notes from a keyboard.