Actually, I think the original was about Bagpipes, not accordions. I thought it was Mark Twain, but can't find it attributed to him. Rather, at http://uncyclopedia.wikia.com/wiki/Bagpipes, it's attributed to Ronnie Corbett, whoever he is. "Definition of a 'gentleman' - someone who knows how to play the bagpipes but doesn't," - Ronnie Corbett.