Davy Stewart's incredible recording of "The Dowie Dens of Yarrow" is one of my favourite recordings of traditional song (not least because it is a rare example with instrumental accompaniment). I find it hard to believe that the wild, avant garde dissonances he produces could possibly have been made on anything other than a piano accordion with a full set of basses. I only wish I could do the same on my melodeon! I'm not sure how the pipes could have inspired a noise like that, either.