Black Sabbath topped the album charts this week, reaching number one a mere 43 years after they last held the spot with Paranoid in 1970.
Interest in the band is currently sky high – but for those who weren't around during Sabbath's heyday, it can be difficult knowing where to start with their back catalogue.
If you're a long-term Sabbath-listener, we'd like your help: later this week we'll be putting together a playlist of 10 essential tracks for people who've never listened to Black Sabbath before.
What is the one song you think should be on the list - and why? Tell us what you think the ultimate Black Sabbath song is, either in the comment thread below, or by tweeting us at @guardianmusic with the hashtag #BlackSabbath.
