An accordion is a type of musical instrument that produces sound through the compression and expansion of air by bellows, which causes reeds to vibrate. Unlike woodwinds, which require air to be blown directly into a mouthpiece, an accordion uses a system of buttons or keys to control which reeds are activated.

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These reeds are typically made of metal, and when air passes over them as the bellows are moved, they vibrate to create musical notes. The accordion is often associated with folk music and is used in various genres around the world, but it is not classified as a woodwind instrument since it does not rely on direct wind flow from the player’s mouth. Instead, the air is generated mechanically by the movement of the bellows.