Wheatstone concertina 1922
the Flight of the Bumble Bee mentioned above), but is more restrictive if you want to play melody with low accompaniment, e.g. Normally the English concertina has 48 keys, but some models had 56.
The extra 8 keys are at the high end of the scale and are thus not so useful on the treble, but they can be helpful in tenor-trebles and baritones.
The layout of buttons is very logical and fully chromatic, and permits very high speeds to be achieved when playing melody (e.g.
Concertina bands were formed, playing marches and other popular pieces (and commemorated to this day by the Concertina Brewery, who brew in the cellar of the old Mexborough Concertina Band Club in South Yorkshire).
It also became a favourite of traditional musicians throughout the British Isles.
ENGLISH CONCERTINA This is the original concertina as invented by Wheatstone.
You can recognise one by the 4 parallel rows of buttons and by the supports for thumb and little finger on each end.