The viola organista was Leonardo da Vinci’s stringed keyboard instrument design. Leonardo sketched versions of it in notebooks during the late 15th and early 16th centuries, combining a keyboard with bowed strings.
Pressing a key would select a string while rotating wheels or a belt rubbed the strings continuously, producing a sustained sound similar to a viola or other bowed instrument. The concept attempted to give a keyboard player the expressive, continuous tone of a bowed string section.
No instrument built by Leonardo is known to survive, and his drawings leave room for interpretation. Several modern makers have constructed playable versions, including instruments based on the Codex Atlanticus sketches.
The name can cause confusion because the viola organista is not a conventional viola and does not use a standard bow. It is also distinct from the hurdy-gurdy: both use friction to sound strings, but the viola organista is controlled through a keyboard.