A family of free aerophones similar to an accordion. Invented in 1844 by Sir Charles Wheatstone, the concertina was created with buttons on both ends of the bellows rather than the keyboard of the accordion.See also accordion. Concertina a small, hexagonal-shaped instrument with bellows, similar to the accordion, but without a piano-like keyboard. Instead, it has only studs, operated by the fingers, which produce only a relatively small number of notes. Concertinas were popular in the 19th-century but have now been virtually replaced by the accordion