Leonardo da Vinci designed the viola organista by combining bowed strings with a keyboard mechanism.
The instrument’s keyboard controlled small wheels or bows that rubbed against strings, producing sound in a way related to a violin or other bowed instrument. Unlike a conventional keyboard instrument, its strings were not struck by hammers or plucked by quills. Leonardo explored several versions in his notebooks during the late 15th and early 16th centuries.
No surviving instrument proves that Leonardo completed a playable original. Modern builders have reconstructed versions from his drawings, and some replicas have produced music. The concept belongs to a wider Renaissance interest in mechanically controlled instruments and continuous sound.
The viola organista is sometimes confused with an organ because of its name and keyboard. It does not create sound through organ pipes. Its distinctive idea is the mechanical bowing of strings, controlled by keys.