Ah, the "meaning of Celtic" discussion. A lot of Quinn's theories are based on quite subjective assessments on what music sounds like, which I suppose is as good a place to start as any. Now, I dont know if he's got as far as Afghanistan, but I recorded an Afghan singer in Stoke a couple of years back who sounded quite remarkably Irish I thought; more so than any north African or Arab that I've heard. This fits in with Quinn's theories about lands beyond Russia, though I'm not sure how it fits in with the initial Atlantic Coast Culture stuff that started him off. I will have to read up on this in more detail.