Born on September 4, 1960, Kim Thayil became the lead guitarist and co-founder of Soundgarden, helping create one of the heaviest and most distinctive sounds to emerge from Seattle. Active with the band from its formation in 1984, Thayil developed a guitar style built around massive riffs, unusual tunings, psychedelic textures, and the weight of classic heavy metal. His playing became essential to albums like Louder Than Love, Badmotorfinger, Superunknown, and Down on the Upside, powering songs including "Jesus Christ Pose", "Outshined", "Spoonman", and "Fell on Black Days". While Soundgarden became one of the central bands of the grunge movement, Thayil's deep connection to heavy metal helped ensure they always carried a darker and heavier edge. His unconventional riffing and unmistakable tone made him one of alternative rock's most influential guitarists.

Born on September 4, 1956, Blackie Lawless became the founder, lead vocalist, songwriter, and driving creative force behind W.A.S.P.. After emerging from the Los Angeles metal scene and forming the band in 1982, Lawless built a reputation around confrontational theatricality, towering stage presence, and songs that combined heavy metal aggression with huge melodic hooks. His voice and songwriting drove classics like "I Wanna Be Somebody", "Wild Child", "Blind in Texas", "Love Machine", and "The Headless Children". As W.A.S.P. evolved, Lawless pushed beyond the band's early shock-rock reputation into darker and increasingly ambitious records, most notably the concept album The Crimson Idol. Active professionally since the 1970s, Blackie Lawless remains one of American heavy metal's most distinctive frontmen.

On September 4, 2001, System of a Down released Toxicity, their second studio album and the record that transformed them into one of the most important heavy bands of their generation. Combining alternative metal, frantic rhythmic shifts, Armenian musical influences, political fury, absurdist humor, and unforgettable melodies, the album sounded like virtually nothing else in mainstream rock. Featuring "Chop Suey!", "Toxicity", "Aerials", "Prison Song", and "ATWA", the album reached No. 1 on the Billboard 200. "Aerials" later topped both Billboard's Mainstream Rock and Alternative charts, while "Chop Suey!" became one of the band's defining songs. More than two decades later, Toxicity remains a landmark of 21st-century metal, capturing System of a Down at the moment their strange, volatile, and fiercely original sound conquered the mainstream. Produced by Rick Rubin and Daron Malakian.