What Leonardo da Vinci invention was a musical instrument played by pressing keys?

Leonardo da Vinci’s viola organista was a keyboard musical instrument played by pressing keys.

Leonardo designed the instrument in the late fifteenth century. It combined a keyboard with continuously rotating, rosined wheels or bows that rubbed strings, producing sound in a way related to bowed string instruments. The player could control several pitches using the keys while a mechanism kept the bowing action moving.

The viola organista was not a conventional organ, despite its name. It had no pipes producing the sound in the normal organ manner. It was also not a standard viola, because the performer did not hold it under the chin or operate it with a separate bow.

Leonardo never produced a surviving working original. Modern instrument makers have constructed reconstructions from his drawings, allowing researchers and musicians to investigate how the unusual keyboard-string mechanism may have sounded.