To the vulgar boatman. the point I was trying to make, is that there is some music that is not suited to the concertina.where the composer has indicated, for the piano forte or the harpsichord that the left hand should be quieter than the right, this cannot be acheieved on one concertina .I am aware the pianoforte is the ideal instrument for this, but to a lesser extent the harpsichord can achieve some variation between left and right as regards dynamics, the concertina cannot. In my opinion music for two harpsichords is best played on two concertinas rather than one concertina. I apologise if i did not make myself clear at the beginning, but hope I have now done so.Some music is not suited for the   solo concertina, that includes some classical piano music and music for two harpsichords, and flamenco guitar music.