O'Neill didn't include waltzes either. Possibly he, like Comhaltas, concentrated on what they perceived to be "pure" Irish music, and felt anything called a polka must have originated outside of Ireland. Why he did not apply thge same reasoning to hornpipes and jigs is a matter of conjecture.This is a very interesting topic, and to discuss it in detail, as many have, is to open several buckets of worms. There is a lot about sliabh luachra music that is extremely odd and "un Irish", as there is in Donegal too of course.