Oh, dear Gibb!

"She sings American-style music". So?

I think you mean she sings music inspired by music created in America; which in turn has its origins in Africa, Eastern and Western European folk music/popular music, and a pile of other sources.

So pray tell me Gibb, if an Englishman performs a blues number, does he have to use an American accent?

If an American sang "Raglan Road" does he/she have to adopt an Irish accent?

And, finally do you think British/Irish singing adopting American accents is "no problem"?