I had seen John Barrowman in the London version of Sunset Boulevard and The Beauty and the Beast. He usually appears at the West End. I think he is of Scottish descent but he was partly raised in America. He has also appeared on a TV series in America.
He doesn't have the best natural voice but he can handle many musical theater best songs well. He released a good album on Broadway songs about a year or two ago called "Reflections on Broadway".