Leonardo da Vinci’s bowed-string keyboard design was the viola organista.
The viola organista combines a keyboard with strings that are sounded by friction from rotating wheels or ribbons. Pressing a key selects a string, while the rotating mechanism continuously bows it. Leonardo explored several versions of this idea in sketches from the late 15th and early 16th centuries.
The instrument was intended to give a keyboard player the sustained, expressive sound associated with bowed string instruments. It was technically ambitious because the mechanism had to keep the bowing surface moving while allowing the performer to select pitches and, in some versions, several strings.
Leonardo’s original instrument does not survive, and there is no firm evidence that he completed a working example. Modern builders have created reconstructions based on his drawings. The viola organista is therefore best described as a Renaissance keyboard-instrument invention or design, not as the direct ancestor of the modern piano.