Swapping out one legendary vocalist for another, Black Sabbath definitely traded up talent-wise when they enlisted Ronnie James Dio. Ozzy Osborne had unique charisma; Dio had pipes (and he was no slouch in the stage presence department). This first of their three outings together (four, if you count their tenure as Heaven and Hell in the 2000’s) found Tony Iommi rejuvenated by this fresh challenge, rising to meet the challenge posed by the New Wave of British Heavy Metal bands that already viewed Sabbath as dinosaurs. “Neon Knights” and the title track alone proved that they were still the apex predators in this particular prehistoric jungle.