The Joe Perry Project, guitarist Joe Perry (Aerosmith), guitarist Brad Whitford (Aerosmith), keyboardist Buck Johnson (Aerosmith), singer Chris Robinson (The Black Crowes), bassist Robert DeLeo (Stone Temple Pilots), and drummer Jason Sutter, were joined onstage by two guests during their September 17 opening set for The Who at the Hollywood Bowl in Los Angeles, CA. This includes Steven Tyler (Aerosmith), who performed Aerosmith’s “Walk This Way” and a cover of Tiny Bradshaw’s “The Train Kept A-Rollin’,” and Slash (Guns N’ Roses), who performed a cover of Aerosmith’s “Mama Kin.” You can check out some fan-filmed footage of all that below: