What stringed keyboard instrument did Leonardo da Vinci design to imitate a violin’s sound?

Leonardo da Vinci designed the viola organista, a keyboard instrument intended to produce bowed-string sounds.

Unlike a normal piano or harpsichord, the viola organista used rotating wheels or bows that rubbed against strings when the player pressed keys. Leonardo’s surviving drawings show several possible arrangements, reflecting his habit of exploring mechanisms through repeated variations rather than presenting one finalized machine.

The instrument combined keyboard control with the continuous sound associated with bowed instruments. That made it conceptually different from plucked keyboard instruments, even though it was never established as a standard Renaissance instrument.

Leonardo’s design is often linked to the modern hurdy-gurdy because both use friction to sound strings. The comparison is useful but incomplete: the viola organista was keyboard-operated, while a hurdy-gurdy is played with a hand-cranked wheel and keys.