Of course, many American pop singers affect American accents that are not their own - or maybe not anybody's. Was reading some comment recently about John Fogarty in that regard. I find it amusing when, from time to time, I will hear some rap/hip-hop guy being interviewed, speaking in a flat, generic middle-class North American accent - then they play his recording, and it's all NYC ghetto .... No different than the C&W singers who sound like they're from back of Butcher Holler - when they sing.

So what you get on those islands on the east of the Atlantic is singers imitating the accents of singers imitating accents .....