It’s always fun to wonder about “what could have been.” What if Jeff Beck had joined the Rolling Stones after Mick Taylor’s departure? What if the Beatles had got back together in 1976 or 1979? What if Tony Iommi had stayed in Jethro Tull? Here’s the one-and-only video of Iommi—the man who would go on to be the mainstay—the rock—behind Black Sabbath—on stage with his one-time band, Jethro Tull.