What Leonardo da Vinci machine combined a piano-like keyboard with bowed strings?

Leonardo da Vinci’s keyboard-and-bowed-string machine was the viola organista.

Leonardo developed designs for the instrument in the late 15th century. It used a keyboard to control strings while rotating wheels or belts rubbed against them, combining the playing method of a string instrument with the layout of a keyboard. The aim was to make sustained bowed sounds available through keyboard control.

Unlike a conventional organ, the viola organista did not use pipes to create its sound. It also differed from a piano because the strings were activated by friction rather than struck hammers. Leonardo produced several related sketches, showing that the idea evolved rather than existing as one single finalized instrument.

No surviving Renaissance viola organista is known. Modern builders have made playable reconstructions based on Leonardo’s drawings, demonstrating the instrument’s musical principle. The name is descriptive: “viola” refers to bowed-string sound, while “organista” signals its keyboard-like operation.