Ronnie James Dio was key in pioneering classic metal's operatic style. Between stints in Rainbow and Black Sabbath, as well as a fertile solo career, the singer set the bar for booming pipes and sword-and-sorcery imagery. From 1975, “Starstruck” captures Rainbow's ability to fold bluesy raunch into melodic neoclassicism. These qualities also shine through on Sabbath's “Heaven and Hell”, whose chilly, streamlined pulse ushered in '80s metal. Recorded under the Dio moniker, the title cut to Holy Diver showcases his talent for painting epic landscapes with screaming axes and hammering drums.