The singing style called in Ireland "sean nos" has analogues in most European, North African and Near Eastern cultures (and doubtless many or most others). That doesn't imply any particular connection; simply that it's a common singing style that goes back a fair bit. A great deal of nonsense is talked about that "black Irish" business (see previous threads). Berbers and Moors are not black.

There's no harm in occasionally pricking the pompous balloon that "celticness" has grown into, but it really isn't important enough to get upset about. "Hakim Bey" has, I think, been mentioned here before; his theories are of the "ancient spaceman" variety; entertaining but ill-informed.