A barrel organ is a mechanical musical instrument made of a series of pipes, and bellows, like any other traditional organ, and of a cylinder studded with staples or bridges or pins corresponding in their placement to a particular tune. The continuous rotation of the barrel causes the staples to come into contact with levers and rods which open valves to let air from the bellows into the organ pipes. The bellows is usually actuated by the same power source which, through reduction gearing or worm gearing, causes the drum to slowly turn around.. Photo credit: Chepry |