John Frusciante gave the Red Hot Chili Peppers the guitarist they needed. Rick Rubin gave them the producer they craved. With the songs tightened up and Frusciante providing hard rock heaviness and colorful guitar licks, Blood Sugar Sex Magik transformed the band and the definition of modern rock. Career-defining tunes such as the unlikely hit ballad “Under the Bridge,” the more expectedly aggressive “Give It Away,” and the chilled-out “Breaking the Girl” proved they could channel their free-stylin’ ways into concise songs that demanded to be heard.