Tony Iommi has twice talked to Robert Plant about making something together, and twice nothing came of it.
"I did say to Robert one time about doing something together, but again, he got his own thing, and I did too," the Black Sabbath guitarist told Katherine Turman of the Los Angeles Times. "Who knows? We've talked about it a couple of times, but he's into a certain flavor of music that he likes to play, which is different to what I play, really. I don't discard anything that way. If something comes up that's a good idea and somebody's into it, then I'm going to have a go."
The two bands spent the early seventies in each other's rehearsal rooms. John Bonham would turn up and ask to play, and once wrecked Bill Ward's kit badly enough that he was never allowed behind it again. During the Sabotage sessions in London, Bonham brought Plant and John Paul Jones down to the studio, sat behind the drums and demanded Supernaut, and the session went out of the window.
Iommi's own solo record, From The Dark, came out on 23 October with Jorn Lande singing on all of it.