Originally formed by Bill Ward, Ozzy Osbourne, Tony Iommi and Geezer Butler, Black Sabbath created Heavy Metal music and changed the course of music forever. Without them, Heavy Rock probably wouldn't have evolved the same way. Also many bands that appeared in the following decades maybe would not even exist. After Sabbath, the Heavy Metal genre evolved and many incredible bands appeared over the years. Ozzy Osbourne talked about many of those groups and once even named, who in his opinion, is one of the greatest Heavy Metal singers of all time. The Heavy Metal singer Ozzy Osbourne said is one of the best of all time Besides being the influential original Black Sabbath vocalist, Ozzy Osbourne became a really successful solo act after being fired by the band and launching his solo career in the 80s. So he had the chance to see many incredible bands up-close and even tour with some of them. One of those groups was Judas Priest and Ozzy said in an interview with Metal Hammer in 2023, that Rob Halford is one of the greatest Rock singers of all time. He praised the band because it was them who replaced him at the Power Trip Festival that year. “It’s brilliant (That the festival chose them). Rob (Halford)’s a great singer and they’re a very good band. He’s been a very dear friend of mine and he’s one of the greatest rock singers of all-time." Curiously, that was not the first time Rob Halford replaced Ozzy Osbourne. In 1992, Black Sabbath accepted to be Ozzy Osbourne's opening act one night. That was something that pissed off Ronnie James Dio. He had re-joined the band at the time and refused to do the show. Dio believed it wasn't the right thing to do, since Sabbath was bigger than his previous singer. To proceed with the show, the band called Rob Halford who replaced him that night. The same thing happened in 2005, when Sabbath reunited at Ozzfest but Ozzy wasn't feeling well that day. So Sharon once again called Halford, who is a big Sabbath fan, to replace him that night. Unlike the first time in the 90s, the band had Bill Ward on drums. "British Steel" is one of Ozzy's favorite albums [embed]https://www.youtube.com/watch?v=9VVFNgbsDC4&pp=ygUVbGl2aW5nIGFmdGVyIG1pZGduaXRo[/embed] Ozzy is really a good friend of the Judas Priest members and loves their work. Talking with Rolling Stone in 2017, the Sabbath vocalist listed the album "British Steel" (1980) as one of his favorites of all time. “What can I say, the guys in Judas Priest. (They) are not only mates of mine from my hometown of Birmingham, but one of the best metal bands of all time. This album had ‘Living After Midnight,’ ‘Breaking the Law’ and ‘Metal Gods.’ British Steel is a classic that will definitely stand the test of time,” Ozzy Osbourne said. As Osbourne said, just like Black Sabbath, Judas Priest was also formed in Birmingham. Although Priest was formed in 1969, just one year after Sabbath, they had many line-up changes until 1974 when they released their first album. Halford for example would only join the band shortly before their first record. Ozzy also had the chance to praise Halford in 2022 when Priest was finally inducted into the Rock and Roll Hall Of Fame. In a special video showed at the ceremony, he said: (Transcribed by Rock and Roll Garage): “He (Rob Halford) can still hit the fucking notes which is mind blowing to me. He is one of my favorite fucking singers.” Judas Priest would tour with Ozzy in 2019 but due to health issues, he had to cancel the shows.