Max Cavalera has been a professional musician since 1984 and has toured the world many times. He was a founder member of the award-winning Brazilian thrash metal band Sepultura before forming Soulfly, an immensely successful group who continue to play headline slots at the world's largest festivals and released eleven studio albums, and whose drummer is his son Zyon. He also plays in Cavalera Conspiracy with his brother Iggor, Go Ahead And Die with his son Igor, and in the supergroup Killer Be Killed.

Joel McIver is the author of thirty-four books and writes for several publications as a journalist. He is also the editor of Bass Player magazine. He has written for Rolling Stone, The Guardian, Metal Hammer, Classic Rock, and he is the occasional guest on BBC. Classic Rock magazine has called him "by some distance Britain's most prolific hard rock/metal author." He wrote the official biography of the world's biggest death metal band, Cannibal Corpse and co-wrote Megadeath's bio from bass player David Ellefson.