With a falsetto so blood-curdling it surely was blessed by Satan himself, King Diamond stands as one of the most distinctive vocalists in all of metal. He first made his mark as the ghoulishly face-painted frontman for Mercyful Fate. In the '80s, the Danish group invented a style of proto-black metal rich in occult prophecy and searing, neoclassical-style dynamics; the singer's solo material largely sticks to this winning formula. But as 1987 conceptual landmark Abigail demonstrates, his music often displays a heightened sense of melody and a flair for gloomy, theatrical arrangements.