Tony Iommi made a special appearance this morning (Aug. 26) inside an enclosed glass chamber to raise awareness about the plight of lonely cancer patients.

The Black Sabbath guitarist, diagnosed with lymphona in 2012, took part in a demonstration of the MacMillion Cancer Support's isolation box as part of its "Not Alone" campaign at the Bullring Shopping Center in Birmingham, England. Those inside the box can see in, but the person inside can not – illustrating the sense of separation many cancer victims face.

Iommi, in an interview with BBC News, compared it to a booth in a recording studio. "I was in a bubble for a while," he said, "just like the isolation box."

Black Sabbath was, in fact, in the midst of recording a long-awaited full-length studio reunion with erstwhile frontman Ozzy Osbourne when doctors discovered Iommi's cancer. Sessions were moved from Los Angeles to England so that Iommi could begin treatment.

"When I was diagnosed, I was absolutely devastated," Iommi says. "They're talking to me, saying, 'You've got stage three,' and it's going in my head and I just felt somewhere else. And it was only later when I really broke down. I thought, 'That's it; it's the end.' And you really think that, but it's not. There are people who can help."

The completed 13 became the first album with Osbourne since 1978's Never Say Die and the first with bassist Geezer Butler since 1994's Cross Purposes. It shot to No. 1 in both Black Sabbath's native U.K. and in America, marking the band's first-ever stateside charttopper. Tony Iommi has since gone into remission, Butler confirms.

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