bandoneón

The bandoneón is a type of concertina, part of the accordion family, played by pressing buttons on two opposite panels while expanding and contracting bellows. It produces musical notes via free reeds, and unlike many piano accordions, the pitch of each button can differ depending on whether the bellows are pushed or pulled.

Originating in Germany in the 1830s, the instrument was developed by Heinrich Band and named for him. It gained popularity in central Europe and the Americas, and by the late 19th century it had become a defining instrument in Argentine tango, where it is closely associated with Buenos Aires orchestras and soloists.

Construction commonly features a right-hand keyboard beside a left-hand bass/chords keyboard, though layouts vary. The right side carries melody buttons; the left supplies bass notes and chords. Modern bandoneóns come in several sizes and configurations, with treble button counts typically ranging from around 50 to over 70, and a separate bass section providing a range of chords and bass notes. The system often uses a bi-directional button layout, meaning the same button produces different pitches depending on whether the bellows are pushed or pulled.

In tango, the bandoneón is central to harmonic and melodic texture, yielding a mournful, expressive tone. It reached peak popularity in the 20th century through composers and performers such as Aníbal Troilo and Astor Piazzolla, the latter leading the nuevo tango movement. Today, the bandoneón remains a symbol of tango and is used in folk, classical, and contemporary music worldwide.