The Rock In Rio date marks Metallica's final scheduled live show of 2015. In between live dates, the group have been in the studio this past year working on the follow-up to 2008's "Death Magnetic."

In April, guitarist Kirk Hammett revealed that he lost hundreds of riff ideas for the band's next album when he lost his phone late last year. "I lost my iPhone containing two hundred and fifty musical ideas," said Hammett. "And I was crushed. It didn't get backed up. And when it happened, I was bummed out for about two or three days. I walked into the house. My wife saw me and she said, 'Uh-oh, what's wrong? Did you get a phone call from a relative?' I said, 'No.' She said, 'What's going on?' I told her, and she understood."