At first, Chili Peppers frontman Anthony Kiedis didn’t know if he wanted his band to work with infamous producer Rick Rubin for what became 1991’s Blood Sugar Sex Magik. Somehow he felt that the chemistry might not be right. “We didn’t know if he would be able to blend in well, what with Slayer and the boiling goat heads of Danzig and all,” Kiedis admitted later, referring to Rubin’s previous work. “But he turned out to be a completely open-minded, free-flowing, comforting spirit.”