Leonardo da Vinci designed the viola organista, a keyboard instrument with strings sounded by rotating wheels.
The concept appears in Leonardo’s notebooks, especially the Codex Atlanticus. A player would press keys, while a mechanism brought strings into contact with a continuously rotating wheel or wheels. This arrangement was intended to combine the keyboard’s control with the sustained sound of bowed strings.
Unlike a conventional piano, the viola organista was not based on hammers striking strings. It also differed from a normal viol or violin because the performer did not directly draw a bow across each string. Leonardo produced several related drawings rather than a single universally standardized final instrument.
The design was not widely built in Leonardo’s lifetime. Modern makers have constructed playable versions, including instruments based on the surviving sketches. The name is sometimes confused with Leonardo’s other musical invention, the viola organista’s close relative, the organ-like keyboard concept; it should not be confused with an ordinary pipe organ.