Green Day will contribute "Working Class Hero" to Instant Karma, a John Lennon tribute album due out on Wednesday June 20. All proceeds from the album will go to Amnesty International's campaign to end genocide in the Darfur region. The album will also feature contributions from The Cure, Black Eyed Peas, Jack Johnson and Willie Nelson. Green Day are also set to feature in the forthcoming Simpsons film, which hits big screens in the US on Friday July 27.