What automated drum instrument did Leonardo da Vinci design for military marches?

Leonardo da Vinci designed a mechanical drum for automated military marches.

The device used a rotating cylinder with projecting pegs to control drumsticks. As the cylinder turned, the pegs could lift and release the sticks in a programmed sequence, producing rhythm without a human drummer striking the drum directly. Leonardo’s concept shows how mechanical timing could be applied to music and spectacle.

The machine was associated with a larger moving or wheeled mechanism described in Leonardo’s notebooks. It may have been intended for military display, ceremonial processions, or court entertainment. The exact final form is uncertain because Leonardo left sketches and notes rather than a complete surviving prototype.

This invention is sometimes confused with Leonardo’s famous mechanical lion or armored automaton. Those were separate designs. The drum mechanism is specifically a programmable percussion device, an early example of mechanical music rather than a powered vehicle or humanoid robot.