“Ozzy would never stand in front of the bass rig. He told me to turn it down one night, so for a laugh I turned it up”: Geezer Butler names the Black Sabbath album that captured his favorite bass tone

Geezer Butler of Heaven and Hell recording at the Rockfield Studios on July 25, 2007 in Monmouth.

Before bands like Metallica, Slipknot and Rage Against the Machine – before the term “heavy metal” even existed – Black Sabbath’s colossal riffs and pure power set metal’s mood, with Terry “Geezer” Butler’s brooding basslines stoking the fires of metal’s foundry.

Black Sabbath didn’t invent the rock riff, but Butler and guitarist Tony Iommi used it in a way that defined a genre. Bending strings as if they were made of putty, Butler’s loud and gritty attack underscored the earnestness of his dark lyrics, sung with spine-chilling intensity by Ozzy Osbourne.