Leonardo da Vinci designed the viola organista, a keyboard instrument with mechanically bowed strings.
The instrument combined a keyboard with a mechanism that brought rotating, bow-like surfaces into contact with strings. Pressing keys selected the strings and produced notes, while continuous rotation supplied the bowing action. Leonardo explored several versions of the concept in drawings made during the late 15th and early 16th centuries.
The viola organista was intended to combine the expressive sustained sound of bowed strings with the controllability of a keyboard. It was not the same as a piano, whose hammers strike strings, or an organ, whose pipes produce sound through air. Leonardo’s mechanism instead relied on friction between the strings and moving bowing elements.
No known original Leonardo viola organista survives. Modern instrument makers have built reconstructions from his drawings, demonstrating the basic musical idea while making practical decisions where the sketches leave details unresolved.