What instrument did Leonardo da Vinci invent using bowed strings beneath a keyboard?

Leonardo da Vinci invented the viola organista, a keyboard instrument using bowed strings. His drawings from the late fifteenth century show strings sounded by rotating wheels or belts, with keys selecting individual notes.

The instrument combined features of a keyboard and a bowed string ensemble. Pressing a key would bring a string into contact with a continuously moving bowing surface, allowing the player to produce sustained tones without directly handling a bow.

Leonardo never built a confirmed working viola organista. The concept survives in several notebooks, and modern instrument makers have constructed interpretations of the design. These reconstructions show that the basic mechanism can work, though details vary because Leonardo’s sketches are incomplete.

The viola organista is sometimes confused with the hurdy-gurdy, which also uses a rotating wheel to bow strings. The crucial difference is the keyboard-based note selection and Leonardo’s proposed arrangement of multiple bowed strings.