A four-album run in just over two years is, potentially, a creative-sapping disaster for any band, but with their fourth album – delivered here in multiple formats across CD and vinyl – Birmingham’s Black Sabbath ended a pioneering stretch that not one of their peers could match.

If their first three albums are cornerstones of heavy metal, birthing the form and several of its virulent strains, then 1972's Vol 4 is the granite covering, which sounds a clanging death knell for the flower power pack ("I don't want no Jesus freak to tell me what it's all about," sings Ozzy Osbourne here).

The album proved the band could continue sandblasting everyone in its proximity while stretching out creatively, if not always effectively. Tracks such as Changes (an atypical, forlorn ballad), FX (a time-wasting sequence of echo effects) and Laguna Sunrise (a fragile acoustic instrumental) sit side by side with songs that would become as much touchstones as torchbearers for the genre. Under the Sun, Supernaut, Tomorrow’s Dream, Snowblind, and Cornucopia have the kind of monumental riffs (via guitarist Tony Iommi) that could rupture the San Andreas Fault.

“Gimme 500 words on Black Sabbath,” said the fictionalised music journalist based on  Lester Bangs in Cameron Crowe’s movie Almost Famous. Sorry, bud, but 240 is all you’re going to get here on this (mostly) monolithic metal masterpiece.