The most widely played keyboard squeezebox instrument from the mid-20th century forward.

The concertina is a folding bellows with buttons at each end, although the function and layout of the buttons varies.

The concertina was developed in the early 1800s by English physicist and inventor Sir Charles Wheatstone. A few years later, the Chemnitzer concertina, which is related to the bandoneon, was invented in Germany by Carl Friedrich Uhlig.

Sites offering online sales should be submitted to Shopping: Music: Instruments: Squeezebox.

Sites of manufacturers of bellows-driven free-reed instruments.