Green Day performed their cover of John Lennon's track "Working Class Hero" last night on American Idol. The track is available for preview or purchase via iTunes and is set to benefit Amnesty International's campaign for Darfur.

This cover, along with others from Black Eyed Peas, The Cure, Jack Johnson and Willie Nelson will appear on Instant Karma, a new benefit for Amnesty International's campaign to end the Darfur genocide. Though the United Nations has not been willing to describe the Darfur conflict as a genocide, it is well established that at least 400,000 people have been killed, with an addition 2.5 million displaced by the conflict between the Janjaweed and Fur, Zaghawa, and Massaleit ethnic groups.

A studio version of the song is also available for preview or purchase the song via this link.