"I didn’t realize then that I would never see Ozzy again after that night," Butler writes of the July 5 "Back to the Beginning" show in England.

As news of Osbourne's death spread, artists from across genres and generations paid tribute to the heavy metal pioneer, who collaborated and shared the stage with the likes of Slash, Elton John, Motörhead, and Madonna, as well as Busta Rhymes, Yungblud, and Post Malone.