Just to dip my spoon into the rich stew ... archaeologists are far from agreed about who/what/where the "Celts" were (think about it - every possible colouring of hair and eyes to go with white skin, every possible range of build) and there's mounting evidence to show that they probably didn't "invade" the island commonly known as Britain, either. Read Francis Prior on the subject, or look up a book called "The Atlantic Archipelago". Discovering Celtic artifacts here doesn't mean any more than that the islanders were traders and liked a bit of nice design, but you'll also quickly realise it's hard to disentangle Saxon and Viking art forms from "Celtic".
So in terms of music the blanket terms of Celtic and English tend to wash over me with a faintly irritant effect. Here we quite like "Celtoid" or "Celtish" as a descriptor ...And I've grown used to being told that people can spot my "Celtic" roots in my songs. Haven't yet discovered many ancestors who could have contributed these roots, but hey, once I get over 200 years back who knows what I'll find?
Anne