Leonardo da Vinci designed the viola organista, a keyboard instrument with strings sounded by a rotating bow.
The concept combines features of a keyboard and a bowed string instrument. Pressing keys would select notes, while a rotating wheel or bow mechanism would rub against the strings and produce continuous sound. Leonardo developed several related drawings, but the instrument was not completed in his lifetime.
Its name reflects its hybrid character: “viola” refers to bowed strings, while “organista” points to keyboard operation. Unlike a harpsichord, which plucks strings, the proposed mechanism was intended to create a sustained bowed tone. It also differs from a barrel organ, which uses a pinned cylinder to control pipes.
Modern makers have constructed playable interpretations from Leonardo’s drawings. These reconstructions show how his mechanical curiosity extended beyond weapons, buildings, and flight into musical instrument design.