This article is from the Concertina FAQ, by Chris Timson chris@harbour.demon.co.uk with numerous contributions by others.
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. (There is quite a good picture
in Microsoft's Encarta encyclopaedia, except that it is upside down!).
The larger baritone and bass English concertinas frequently have wrist
straps as well, to help with the greater weight of the instrument.
The two centre rows on each side are in the key of C, the accidentals
are distributed between the outside rows. Playing a scale involves
alternating between the left and right hands. The layout of buttons is
very logical and fully chromatic, and permits very high speeds to be
achieved when playing melody (e.g. the Flight of the Bumble Bee mentioned
above), but is more restrictive if you want to play melody with low
accompaniment, e.g. ragtime.
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.
 
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