# Tony Iommi on writing metal’s greatest riff: “You never know when the magic’s going to strike”

- URL: https://talkfuse.com/story/tony-iommi-on-writing-metals-greatest-riff-you-never-know-when-the-magics-going-to-strike/
- Published: 2026-10-24T04:00:00+00:00
- Updated: 2026-10-24T05:08:40+00:00
- Original publisher: Louder
- Original article: https://www.loudersound.com/bands-artists/tony-iommi-symptom-of-the-universe-riff
- Topics: Entertainment, Music

## Key points

- Iommi says “Symptom of the Universe” began with an unexpected riff.
- He brought the idea to Black Sabbath and built a song around it.
- He says inspiration cannot be predicted.

## Summary

Tony Iommi says the riff for Black Sabbath’s “Symptom of the Universe” came to him unexpectedly, illustrating how songwriting inspiration can arrive without warning. The piece reflects on the creation of a track often regarded as one of metal’s defining riffs.

Iommi wrote the riff while at home and took it to the band, where it became the foundation of the song. He says there is no reliable way to summon that kind of inspiration: musicians can work at their craft, but “you never know when the magic’s going to strike”.

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Summarised by TalkFuse (https://talkfuse.com/). Quote the original publisher for the reporting and link this page for the summary and discussion.