Beck joined Phoenix onstage during the second night of their residency at the Fonda Theater in Los Angeles last night. “Every night we play in LA has to be special,” Phoenix frontman Thomas Mars told the crowd at the end of the Ti Amo cut “Lovelife.” “I think there’s almost one LA reference in every single song that we have. So this is one of your anthems.” The band launched into a cover of Beck’s “Lost Cause,” and Beck himself came out sing it. He stuck around afterwards to perform another one of his own songs, “Jack-Ass.” Watch below.