Accordions are a family of box-shaped musical instruments of the bel-lows-driven free-reed aerophone type, sometimes colloquially referred to as a squeezebox. A person who plays the accordion is called an accordionist. The concertina and bandonion are closely related; the harmonium and American reed organ are also in the same family. It's most prolific use is in European and North and South American traditional music, but also used in popular and folk music. It is known in many different names across the world, including Harmonika, Dragspel, Trekkspill, Oinu Handia and Eskusoinua.