Frontman Max Cavalera, formerly of Sepultura, comments: "A lot of my music is used in war. I have letters from people who were in Desert Storm saying, 'I was flying over the desert with Arise on my headphones and I was f**king sh*t up!'

"I never even imagined when I wrote those records that some people were going to use the music for stuff like that," he continues. "It's wild how my music has traveled. We even have fans in Iran, which is crazy to think about – metal is illegal there. It's outlawed by religion and by the government.