Although similar musical instruments, there are several differences between the two – most notably the buttons. Accordion buttons, known as “bass,” are pushed perpendicular to the bellows. However, concertina buttons are pushed into the instruments, traveling in the same direction as the bellows. Another notable difference is that most accordions feature bass that can play an entire chord, while concertina buttons play only one note, not a whole chord. In addition, accordion reeds are attached to the top edges of their chamber walls, whereas traditional concertina reeds are mounted into slots facing the reed pan.