Machine Gun Kelly sells out Madison Square Garden, the world's most famous arena with Slim on keyboard, Rook on drums, Baze on bass, Jus on guitar and the newest member of the band, Sophie, on guitar. The band has been performing with an amazing level of chemistry and creativity. Mainstream Sellout peaked #1 on the Billboard Global 200. The Mainstream Sellout Tour has had guest appearances from Avril Lavigne, Iann Dior, Trippie Redd, Willow, Travis Barker, Landon Barker, Jxdn and Blackbear.