10 PARANOID BLACK SABBATH (1970)

The definitive choice for guitarists who recognise that rhythm parts are more important than solos, Sabbath’s second album Paranoid saw riff lord Tony Iommi laying down the metal blueprint. Ironman, Warpigs and the title track are the foundation of heavy metal, with Iommi sounding crushing even before the band discovered down tuning. The solos are fluid and exciting, usually improvised as part of live takes with the band; Iommi would add rhythm parts underneath later. But the riffs are the real story. Pete Townshend was known for power chords, but his sledgehammer strumming did sometimes include the major third. It was Iommi who really codified the root and fifth power chord we all play today.

Iommi liked the amps he got free from local manufacturers Laney, but he was always pushing for more gain. On Paranoid he was using a modified Rangemaster treble booster to overload the amp input. To keep the low frequencies tight, Iommi ran the amp’s bass control on 0 while maxing every other control. His Gibson SG’S humbuckers helped too, with more push than the Strat he’d had in Sabbath’s early days. The title track, though, was played on a Les Paul, the only time Iommi recorded with one.