Leonardo da Vinci invented the viola organista, a keyboard instrument using bowed strings.
Leonardo developed the idea in the fifteenth century and illustrated several versions in his notebooks. Pressing keys would select strings, while a rotating mechanism would bring a wheel or continuous bow into contact with them. The result was intended to combine the controllability of a keyboard with the sustained, expressive sound of bowed instruments.
The viola organista was never manufactured during Leonardo’s lifetime. It is not a piano: piano strings are struck by hammers, whereas the viola organista’s strings are rubbed or bowed. Modern instrument makers have built reconstructions from Leonardo’s drawings, but the surviving designs vary, so no single reconstruction can be treated as the exact original.