The Duet Concertina is a type of free-reed musical instrument, similar to an accordion, that is played by compressing and expanding its bellows while pressing buttons. It typically has two sets of reeds, allowing for a richer sound and enabling players to perform harmonies. The instrument is popular in folk music and is known for its portability and expressive capabilities. Originally developed in the 19th century, the Duet Concertina is often associated with traditional music from various cultures. It is distinct from other concertinas, such as the Anglo Concertina and English Concertina, due to its unique layout that facilitates playing both melody and accompaniment simultaneously.