Accordions are a family of box-shaped musical instruments of the bellows-driven free reed aerophone type. The essential characteristic of the accordion is to combine in one instrument a melody section
A piano accordion (top) and a chromatic button accordion (bottom)
Eight-key bisonoric diatonic accordion (c. 1830)
A group of accordionists in Ticino (early 20th century)
A free reed aerophone is a musical instrument that produces sound as air flows past a vibrating reed in a frame. Air pressure is typically generated by breath or with a bellows. In the Hornbostel–Sach
Accordion
…19th-century German Akkordeon, from Akkord—"musical chord, concord of sounds") are a family of box-shaped musical instruments of the bellows-driven free reed aerophone type (producing sound as air flows past a reed in a frame). The essential characteristic of the accordion is to combine in one instrument a melody…
The reeds of an early 20th-century button accordion, with closeup
Sheng with 17 pipes; height is 55 cm (22 inches)
Free reed from a melodion, 1867