Definition & Meaning of "barrel organ"

What is a "barrel organ"?

A barrel organ is a mechanical keyboard instrument that plays music by turning a crank or a handle, which rotates a barrel or cylinder with pinned holes. These pins control the opening of valves that allow air to flow through pipes or reeds, producing sound. The instrument's music is typically pre-programmed on the barrel, which contains a series of holes or pegs that trigger different notes. Barrel organs are often used in street performances and fairs, known for their distinctive, charming sound and the ability to play a variety of tunes automatically.