Leonardo da Vinci designed the viola organista, a keyboard instrument whose strings were sounded by rotating wheels.
The instrument combined features of a keyboard and bowed string instruments. Pressing a key selected a string, while a rotating wheel rubbed against it and produced a sustained tone. Leonardo sketched several versions during the late fifteenth and early sixteenth centuries, but no surviving original instrument proves that he completed a full working model.
The viola organista is often confused with an organ because of its name and keyboard. Unlike a pipe organ, however, it produces sound from strings rather than pipes. It also differs from a piano, where hammers strike strings.
Modern makers have reconstructed the design from Leonardo’s drawings. These reconstructions help demonstrate how his mechanical imagination extended beyond familiar machines into experimental musical instruments.