Leonardo da Vinci invented the viola organista to combine a viola’s sound with a keyboard.
The instrument used a keyboard to control rotating wheels or bows that rubbed against strings, producing a sustained, bowed-string tone. In concept, it brought the expressive sound of bowed instruments together with the ability to play notes from a keyboard.
Leonardo made several designs for the instrument, mainly during the late fifteenth and early sixteenth centuries. Unlike a normal viola, it did not require a player to move a bow directly across the strings. Unlike an organ, it produced sound from vibrating strings rather than pipes.
No surviving evidence shows that Leonardo completed a working version. Modern builders have constructed versions based on his drawings, demonstrating how the mechanism might have operated while preserving the instrument’s experimental status.