There have definitely been a few times when we've learned a little more about the inner workings of Black Sabbath than we might have wanted to know. There are still plenty of cool facts about these metal legends that even hardcore fans might not be aware of, however, and for this edition of You Think You Know Classic Rock?, we've uncovered quite a few of them.

For instance, we all know Ronnie James Dio stepped in to take over the lead vocal position after original singer Ozzy Osbourne was fired in 1979. But do you know who suggested Dio as a replacement? In the above video, we'll fill you in on the details of that story, along with the early near-breakup that was averted after guitarist Tony Iommi briefly joined the ranks of a certain well-known British prog band.

And that's not all: There's also the strange story surrounding the band that recorded a song called "Black Sabbath" the year before Sabbath came along — and included a bassist whose name will be surprisingly familiar to fans. And speaking of Sabbath's debut, how about the mystery that continues to surround the album's spooky cover shot?

It's all right here in this all-new, all-Sabbath installment of You Think You Know Classic Rock?, which offers the details behind all these stories and more — including the distinct method that animal-loving Sabbath bassist Geezer Butler has devised for naming his house full of cats. So what are you waiting for? Hit "play" and start testing your Sabbath knowledge now.

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