To no one’s surprise, the substance-addled Glenn Hughes bowed out midway through Black Sabbath's ‘Seventh Star’ tour in 1986 and opened the door for two relatively unknown singers to step up to Black Sabbath's vacant microphone.

First, American Ray Gillen, who helped Sabbath finish their tour, started laying down vocal tracks before abruptly leaving to join Blue Murder and then Badlands.

Then Birmingham native Tony Martin stepped in. His presence on 1987’s ‘The Eternal Idol’ reinstated Black Sabbath as a pure heavy metal band. It didn't hurt that Tony Iommi penned worthy songs like ‘Ancient Warrior,' ‘Glory Ride’ and ‘The Shining,’ which arguably is the best-ever Sabbath song not sung by "the big two" -- Ozzy Osbourne or Ronnie James Dio.

Critics, fans, music-industry big shots -- they all remained skeptical. But Black Sabbath’s modest comeback starts here.

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