". . . people often sound ridiculous when they attempt to sing in accents which are not their own."

True, some do. But it depends on how well they do it. I heard one fellow once sing a couple of Scottish songs and he did it so well I thought he was a Scot. And I was not the only one. Turned out he was from Indiana.

But he was also an actor, and he had spent some time studying dialects as an adjunct to his work.

Don Firth