Black Sabbath bassist Geezer Butler has described how the term “heavy metal” was first used as a sarcastic way of describing the band’s music, before being coined as the official name of the genre. The musician also went on to describe the backstory behind one of their biggest hits, claiming that the inspiration came from an unlikely source.

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In an interview with The Eddie Trunk Podcast, Geezer Butler, one of the founding fathers of the heavy metal genre, described how he believes the term first came into existence. Stating that the label first came into existence during the early 1970s, the bassist estimates that the phrase was used exclusively in the United States as an insulting context, saying that Black Sabbath ultimately got “stuck with it”.

“When we were on tour in America — I think it was the second tour in the [United] States — I read this review, and the guy said, ‘This isn’t music; it sounds like a bunch of heavy metal being smashed together.’” Butler states. “Somehow that got over to England, and from then on it was like the sarcastic thing they used to apply to us — ‘this isn’t music, it’s a load of heavy metal being smashed together.’ And for some reason, we got stuck with it.”

While intended to be an insult to the band, Butler infers that the members instead sought pride in the label, which eventually distinguished their sound from other artists on the scene. However, this is far from the first time that the term’s origins have been thrown into question; with many crediting Steppenwolf as inventing the phrase in their 1968 hit, Born To Be Wild, with the track’s lyrics reading: “I like smoke and lightnin’/ heavy metal thunder”.

Elsewhere in the interview, the bassist also reminisced over some of the band’s most successful releases, eventually continuing to describe the little-known origins of one of their biggest hits.

Describing the 1970 track, Iron Man, Butler confirmed the biblical message behind the lyrics – stating that the inspiration for the song’s protagonist came from Jesus Christ:

“It was sort of based on Jesus Christ. He’s like, this guy and goes and does good, and then he comes and tries to spread the word and ends up being crucified for telling the truth.” He continues, “that was Iron Man seeing the future and coming back to tell the world how horrible it’s gonna be, and people turn against him. Whereas Jesus died to save people, Iron Man takes his revenge. That’s the big difference.”

The full interview with Geezer Butler can be found on Eddie Trunk’s Spotify.