On two occasions the Judas Priest vocalist Rob Halford saved Black Sabbath's live performances. The first time happened in California, in 1992 when Ronnie James Dio refused to perform since the band was Ozzy Osbourne's opening act and the second time in 2004 at Ozzfest when the original line-up would reunite but Ozzy couldn't perform because of an "attack of bronchitis". The band's main lyricist and bassist Geezer Butler is currently promoting his autobiography "Into The Void - From Birth to Black Sabbath" and recalled in an interview with Rocker Morning Show (Transcribed by Blabbermouth), how the band was received on that second occasion by the fans. Geezer Butler recalls Black Sabbath's performance with Rob Halford "It was great. Rob's from the same area as the four of us. And Tony actually used to manage the first version of Judas Priest. So we all knew each other from the early '70s. And Rob knew all the lyrics to the Sabbath stuff." When Ozzy got ill, Judas Priest were on the same bill as us, and we sort of asked Rob if he wouldn't mind coming on and filling in for Ozzy. He was a bit reluctant, in case he blew his voice out. But then he agreed. And it went great." He continued: "Well, it started off not very well, 'cause everybody's expecting Ozzy, and then there's Rob Halford coming on. And then after the first song, everybody accepted us. They didn't really know what was going on. Why is Rob Halford singing with Black Sabbath instead of Ozzy? And then I think he explained everything after the first song. And then the audience got it. And [it was] a good gig after that," Geezer Butler said. Judas Priest was also formed in Birmingham, England, the same town where Black Sabbath was formed. Even though they were started in 1969, one year after Sabbath, they only released their debut album in 1974. https://www.youtube.com/watch?v=lHyUyPPipJw&pp=ygUeYmxhY2sgc2FiYmF0aCByb2IgaGFsZm9yZCAyMDA1