Reference the classical music aspect - we folk musicians have a tendency to forget the origins of most of the instruments we play...the English and duet concertinas have a much greater claim to playing classical, particularly "light classical", religious, "parlour" and music hall music than ever they had to traditional music. Even the anglo, which lends itself so well to dance music, is, in its more developed forms fully capable of stunning harmonic work, and at the turn of the 20th century, Regondi published a method for the anglo in several volumes which included popular tunes and songs of the day, Sousa marches and bits of Mozart and Beethoven. There was no folk music revival when those things were invented; we got lucky in that the concertina didn't become extinct (which was a damned close run thing) and that one or two talented and somewhat obsessive individuals did so much to promote a new use for the instrument.