Like a classic Metallica song, Birth School Metallica Death is long and epic. Indeed, it's published in two separate volumes and co-written by two journalists. Volume 1 is just out and Volume 2 will follow in 2014.

Gibson.com asked co-author Paul Brannigan (his colleague is Ian Winwood, both ex-Kerrang! editors) about getting inside the heads of the world's biggest metal band…

Was Birth School Metallica Death always going to be two volumes? "Yes, always. Obviously, there are many books about Metallica. But we (Brannigan and Winwood) wanted to make it different. So we decided there'd be a jump-point, from when Metallica headlined Madison Square Garden when they played the "Black" album. Quite an idea of theirs to play an 18,000 people venue just to play a new album. Not many other bands would have done that at the time, or even now. Up to then was volume 1. We were quite hard about it with our publishers. It was two volumes or nothing."

Explain your love of Metallica? "The very first issue of Kerrang! I ever bought, issue 115, had a 5-star review of Master of Puppets. I bought the album, and that was the start. I went back and bought the first two albums. I was onboard, if you like. So the early part of the book was more of a challenge as myself and Ian were 15-16 years old at the time of those records. We weren't there. But people who were there helped us a lot. For the second volume (Brannigan later became Editor of Kerrang!) we were there. Lots of great access."

Do Metallica approve of your book? "I don't know. It's outside their world. We contacted Peter Mensch (Metallica's manager) and he said it was OK to go ahead. It was like when I wrote the Dave Grohl book. Artists are so busy they can spend 10 or 20 years before they are ready to think about putting this stuff down. At that point, they may have forgotten things or want to put out a different version of history. That's why some unauthorized biographies are better."

There's a few references in the book about metal being a teen obsession. Yet Metallica are still playing metal and you are still writing about it… "Adolescent obsessions seem to remain close to people's hearts. Some of the best heavy metal is ridiculous. But for people who have grown-up with a love for the music, they don't mind that. Fans all know the inherent ridiculousness of men running around singing about avenging goblins, nuclear armageddon, or not being giving enough cookies by their babysitter.

"But it's part of the appeal. Heavy metal is supposed to be larger than life. The drama, the melodrama, is all part of it. Led Zeppelin, Queen, Black Sabbath, Iron Maiden… they all have ridiculousness. That's part of the joy of the music."