"I wrote 'Coma' in my heroin delirium," Slash told Guitar Magazine
in 2011. "That's a song that I'm still proud of. There's not a lot of 'technique' – it's a pretty straight up kinda Slash approach. But the thing that's really interesting was the vamp-out, which was this circular rotating chord progression that never ended: the same chord progression every time, but it just kept changing key. That was my mathematical musical discovery. I just stumbled on it and it's very much me doing my thing… but it worked."
Bertrand - Paris, France