Badly phrased, I think. There are some stereotypical wonderful folk voices of black female folk singers - think Odetta, think the singer whose name escapes me but went into childrens TV and made a commercial for the conservatives at the last election (or of course think Jo-Ann Kelly who was white). There is that type of delivery and belting voice. It is a stereotype and it is perceived as a "black" delivery.

I suspect it is a case of engaging mouth before putting brain in gear, rather than anything sinister.