Ozzy Osbourne will come out of touring retirement and reunite with the full Black Sabbath lineup for the first time in 20 years.

One of the most legendary heavy metal bands of all time is reuniting.

The concert, titled Back to the Beginning, will mark the first time the original four members of Black Sabbath — Ozzy Osbourne, Tony Iommi, Geezer Butler and Bill Ward — will perform together in 20 years. A plethora of other huge rock and metal musicians, including Metallica, Slayer, Alice in Chains, Anthrax and more will also play at the event.