Some can do accents... some cannot. Jean Redpath could slip into an American 'country' accent quite well..... and my wife, who is 2nd generation Italian, has a very good ear for other languages. I'm sure a native speaking Scot could tell she was NOT perfect, but she does Hamish Henderson's "Farewell to Sicily" well enough to satisfy Ed Miller, from whom she learned it.

I sometimes sing "The Twa Corbies", and I can't imagine Anglicizing it, whether or not I manage a Scottish accent perfectly. I can 'hear' the right sounds in a song, even though I have not always practiced reproducing them just right.