Produced by Rick Rubin , its musical style differed notably from the techniques employed on the band's previous album Mother's Milk , and featured minimal use of heavy metal guitar riffs. The album's subject matter incorporates sexual innuendos and references to drugs and death, as well as themes of lust and exuberance. It was the Chili Peppers' introduction into worldwide popularity and critical acclaim, although guitarist John Frusciante quit the band mid-tour in returning in due to his inability to cope with its popularity. The album is recognized as an influential and seminal component of the alternative rock explosion of the early s, with Steve Huey of AllMusic calling it "probably the best album the Chili Peppers will ever make". The band's previous album, 's Mother's Milk , became the band's second album to enter in the Billboard , peaking at number 52 and at the time the biggest of their career.