Bandoneon is a nice instrument because in a small "box" you have an unexpected extension: in the 33/38 Rheinische Tonlage the left side (bass side) starts from C2 and reaches up B4 (3 octaves), while the right side ("singing" side) starts from A3 to B6 (3 octaves again).
The 2 sides extensions partially overlap, for a total extension of almost 5 octaves. Not bad for a little squeeze box!
Let's see a comparison with some musical instruments in the next infographics:
And what about 144 tones Bandoneons?
The 144 bass side of 144 models also starts from C2, and arrives up to A#4, while on right side it starts from G3 and reaches up to A6.
The range of 144 is slightly less than 142 model, but the total extension is sacrificed in favor of a more coherent keyboard, in fact chromatically complete for both opening and closing.
