Green Day frontman Billie Joe Armstrong joined Sex Pistols and Frank Carter at Tons of Rock Festival, where they performed 'Anarchy In The UK' together. Fans were surprised and delighted by the collaboration, with one calling it the "punk rock treaty of Versailles." Armstrong has previously spoken about the impact of Sex Pistols on his music, while former Sex Pistol John Lydon has been critical of Green Day and the recent reunion shows with Carter. Tons of Rock Festival in Oslo also featured headliners Muse, Kaizers Orchestra, and Avenged Sevenfold, among others.