The Trinity College Anglo-style, 20-button Concertina is a handcrafted, authentic reproduction of the original model introduced in the early 19th century in England and Germany. This Anglo model is a “bisonoric” design-much like today’s harmonica-where a different note is produced by the “push” and “pull” motion of the bellows. This type of mechanism lends itself perfectly for many styles of ethnic or “folk” dance music.