Tony Iommi

• Tune down at least a half step (Eb) — C# for early Sabbath, D for later material
• Use the neck pickup for maximum thickness on riff-based parts
• The Rangemaster boosted the treble into the amp — not a modern overdrive pedal
• Iommi plays with custom plastic thimble fingertips; use a slightly softer pick attack
• Power of three: palm-muted root, open power chord, tritone (the "devil's interval")
• Slow, deliberate picking tempo — early Sabbath riffs are slower than they sound
• Amp EQ: bass 7, mid 5, treble 6, presence 6 — dark but articulate
• String bends are minimal; Iommi's expression comes from riff and vibrato on single notes
• Study "Iron Man" and "Black Sabbath" for the two defining Iommi riff archetypes
• The Rangemaster treble booster clips the upper midrange harmonics, adding a singing quality to single-note riffs that a modern overdrive pedal cannot replicate — modern equivalents include the Catalinbread Naga Viper and the Effectrode PC-2A, which aim to replicate the germanium transistor character
• Iommi lost the tips of two fretting fingers in an industrial accident and solved the reach problem by tuning down and using lighter strings than typical heavy metal players — if you play standard tuning with heavy strings, the riffs physically feel wrong because they were conceived on a lighter, lower-pitched instrument
• The tritone interval (b5 or #4 in scale terms) appears in nearly every Iommi riff as a tension point — practise power chord shapes that include the tritone (root + flat 5 below or above) across the fretboard in all positions to understand how he built menace into simple two-note shapes

Tony Iommi invented heavy metal. After losing the tips of two fingers in an industrial accident, he tuned his strings down — creating the dark, slow, heavily de-tuned riff vocabulary that launched a genre. His SG into a loud Laney, pushed with a treble booster, is the foundation of all heavy music that followed.

Iommi invented heavy metal guitar tone with three deceptively simple ingredients: downtuned SG, Laney amplifier, and homemade thimble fingertips on his right hand (he lost the tips of his middle and ring fingers in an industrial accident). Every heavy riff followed.