It might finally be time to stop thinking about Holy Diver as a guilty pleasure.

[xrr rating=2.5/5]In theory it’s a great idea. Ronnie James Dio was one of the great heavy metal vocalists, fronting bands as diverse in approach as the pop-metal of Rainbow, the dense textures of Black Sabbath and the keyboard-and-power-chord concoction of Dio. His operatic holler was truly impressive, and his knack for quirky vocals—“We’re a ship without a storm, the cold …