A large family with several internal divisions
Bandoneons are basically divided in 2 categories: the unisonoric models (inappropriately called chromatic) and the bisonoric (inappropriately called diatonic), with several different versions within each category also. For example, in unisonoric versions you find at least 3 different layouts: Peguri (originally spread in France and Belgium and now in all Europe), Kusserow (very rare, with small diffusion in Europe) and Standardbandonion (invented by bandonion virtuoso Heinz Schlegel, and largely unknown), but the list goes on.
