There is no doubt that the melodeon has moved on from the Hohner two row that you could buy in Bell's Accordions at Surbiton,The Italians first displayed some wonderful boxes in France many years ago and with a few extra notes and wonderful tone ,it has made the instrument far more versatile.It is easier to play than the Concertina and certainly louder than a fiddle, or pipe and tabor.North West Morris certainly is enhanced by a band that includes a melodeon. My original posting was not anti melodeons although there is always a tendency for a bit of banter when you mention them.
Al