On September 24, 1991, Nirvana released Nevermind through DGC Records, an album that would completely upend the music industry within months. The record paired Kurt Cobain's raw, melodic songwriting with the rhythm section of Krist Novoselic on bass and Dave Grohl, newly arrived on drums, giving the band a heavier, more powerful sound than their debut Bleach. Recorded largely at Sound City Studios in Van Nuys, California, on a modest budget far smaller than most major label albums of the era, Nevermind opened on the charts at No. 144, but "Smells Like Teen Spirit" became an unstoppable anthem, and by January 1992 the album had knocked Michael Jackson's Dangerous out of the No. 1 spot on the Billboard 200. Alongside "Come as You Are," "Lithium," and "In Bloom," the record effectively ended the commercial dominance of hair metal overnight and pushed grunge into the mainstream, later going Diamond in the US. Produced by Butch Vig and Nirvana.

Born on September 24, 1969, Shawn Crahan, known onstage as "Clown," became a co-founder and percussionist of Slipknot, the masked nine-piece that turned heavy metal into a genuinely terrifying spectacle. Wearing one of the band's most unsettling masks and designated member #6, Crahan pounded on a rig of trash cans and scrap metal alongside fellow percussionist Chris Fehn, adding to the chaotic, industrial low end beneath Slipknot's assault. Beyond performing, Crahan has directed music videos and films for the band and served as an early creative architect of its visual identity, from the masks to the numbered jumpsuits. Decades after Slipknot's formation in Des Moines, Iowa, Crahan remains the band's longest tenured and only original member still active in the lineup.

On September 24, 1990, Megadeth released Rust in Peace, the album many consider the pinnacle of technical thrash metal. Fronted by Dave Mustaine, the band assembled its most virtuosic lineup yet with guitarist Marty Friedman and drummer Nick Menza joining alongside bassist David Ellefson, delivering intricate, lightning fast riffs and jarring time signature shifts that raised the bar for the entire genre. The album produced staples like "Holy Wars... The Punishment Due," "Hangar 18," and "Tornado of Souls," tracks still considered among the most technically demanding in metal, with lyrics touching on war, paranoia, and the Cold War era. Rust in Peace reached No. 23 on the Billboard 200 and was later certified platinum. Produced by Dave Mustaine and Mike Clink.