Muse fans are planning to mark the band's landmark two-night stand at London's Wembley Stadium this summer (07) by staging a singalong in the British capital's Trafalgar Square. Editors of fan website are encouraging followers to meet at the central London attraction on 15 June - the day before the first concert - to sing from 6pm to 9pm. However, anybody wanting to take part must first register with the fansite. The singalong will raise funds for charity The Helen Foundation.