The song "Black Sabbath" opens with one of the most evil sounds in music — a tritone also known as the 'devil's interval' — and in a new podcast exploring the relationship between the devil and heavy metal, Sabbath founder Tony Iommi recollected his reaction after first playing the series of notes on guitar.

In the third episode of Backstaged: The Devil in Metal, hosted by Loudwire contributor Jon Wiederhorn and published by Diversion Podcasts, both bassist Geezer Butler and Iommi discussed the infamous tritone and the profound impact it had on helping a wayward blues band find a definitive musical direction, which subsequently served as the foundation for the entirety heavy metal.

As Wiederhorn noted in the "Black Sabbath and The Root of All Evil" episode, the three-note series was perceived as sinister at earlier points in music's history, though was never outright banned by the Catholic church in the Middles Ages and Renaissance, as had been the rumor.

Composer Gustav Holst, however, used the devil's triad in his career-defining work, The Planets, a seven-piece orchestral suite which featured the iconic "Mars, The Bringer of War." Butler, in particular, was greatly influenced by this stirring, dark piece of music.

"I was particularly interested in The Planets and 'Mars' by Gustav Holst. There's a sort of tritone in that and I was always playing that on bass funnily enough before we even started writing songs and I think subconsciously it may have influenced Tony," Butler recalled.

The three-note selection was also utilized by both Jimi Hendrix ("Purple Haze") and Iron Butterfly "(In-A-Gadda-Da-Vida"), but, despite the popularity of those songs, the triad was not under as intense focus as it was later on when Black Sabbath authored their eponymous track.

Iommi recalled, "Just one day we were in the rehearsal room and I started playing, as I did, ideas and this riff came out and I thought, 'God!' I really liked it and the other guys said, 'Ah, that's really good. We really like that."'So, I put more to it and that was it, it became 'Black Sabbath.'"

"We built it up, but that was immediate — once we'd done that song, that was the direction and we knew where we were going then from that first riff. It just gave us a certain feeling," the guitarist continued.

The feeling that was instilled in him when he first played that riff is quite vivid as Iommi looked back, "I remember when I first played that riff, all the hairs stood up on my arm and I knew that was it. 'That's it, this is where we're at, this is what we're doing.' It was just like being told, 'This is what you're doing and this is where you're going.'"

Anthrax guitarist Scott Ian also commented on how revolutionary those three notes wound up being in regards to Black Sabbath's detachment from blues rock as they pursued an entirely new and fresh sound.

"If evil had a sound, that’s what Tony was touching on with a song like 'Black Sabbath' or even 'The Wizard' …People hadn’t done that yet, it wasn’t the blues," Ian exclaimed, noting, "He was playing chord combination that his predecessors and his contemporaries were not using. Almost everything at that point whether it’s [Led] Zeppelin, Hendrix or Cream or anyone else playing heavy rock music, it’s still very much based in the blues."

Listen to the full podcast episode below.

Backstaged: The Devil in Metal — Episode 3: "Black Sabbath & The Root of All Evil"



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