Green Day stunned America on the finale of talent show American Idol last night (23May07) with a performance of John Lennon's WORKING CLASS HERO. The punk trio's surprise appearance on the hit show was staged to promote a new album of Lennon covers, Instant Karma: The Amnesty International Campaign to Save Darfur. The performance marked the first for any acts appearing on the charity album, which will help raise funds and awareness for Amnesty International's efforts for Darfur, Sudan. Green Day singer-guitarist Billie Joe Armstrong says his group chose to perform Working Class Hero on the album because "its themes of alienation, class, and social status really resonated with us." The two-CD set, which also features Lennon covers from acts like Christina Aguilera, U2, Avril Lavigne, Snow Patrol, Lenny Kravitz and R.E.M, will be released in July (07).