Leonardo da Vinci designed an organ gun, a multi-barreled weapon intended to fire repeated volleys.
The weapon arranged many small cannon barrels in parallel rows or on a frame. After one group fired, the frame could be repositioned or another loaded group could be used. The arrangement aimed to increase the rate of fire compared with a single muzzle-loading cannon.
The name comes from the resemblance between the rows of barrels and the pipes of a musical organ. It does not mean that the weapon used musical sound or functioned like a modern machine gun. Each barrel still required loading, and Renaissance gunpowder weapons had serious limits in accuracy, reliability, and reloading speed.
Leonardo’s military notebooks contain several proposals for improving artillery and battlefield weapons. His organ gun was a design concept rather than a modern automatic firearm, and surviving drawings are the main evidence for it.