Accordions are a family of box-shaped musical instruments that are played by compressing or expanding a set of bellows, while pressing buttons or keys, to allow air to flow across reeds made of brass or steel. These reeds vibrate to create the sound. Because of the action needed to make a sound, accordions can also be called squeeze boxes.

Accordions can be found in many different forms around the world and are often used in traditional and folk music.