What Leonardo da Vinci invention used a drum with pegs to create a repeated musical rhythm?

Leonardo da Vinci designed a mechanical drum that used pegs on a rotating drum to create a repeated rhythm.

The device was part of his interest in automatic machines. As the drum turned, its pegs operated mechanisms that struck the drum surface, producing percussion without a human drummer continuously playing it. The rhythm could be altered by changing the arrangement of the pegs.

This invention belongs to the same broad tradition as Renaissance automata, machines designed to perform actions through cams, gears, springs, and programmed sequences. Leonardo's work connected mechanical engineering with entertainment and spectacle, both important at European courts.

The mechanical drum is sometimes confused with later music boxes. A music box normally uses pins on a rotating cylinder to pluck tuned metal teeth, while Leonardo's device was a percussion machine. Reconstructions help explain how the mechanism may have worked, but surviving drawings do not establish that Leonardo built a complete working example.