Overview:A world-class line-up of musical stars from Sir Paul McCartney and Sir Elton John to current chart toppers Jessie J and Ed Sheeran will perform at a spectacular free concert to celebrate the Queen’s Diamond Jubilee this summer. Ten thousand tickets are to be given away through a public ballot for the event, to be held outside Buckingham Palace on June 4, while millions more will be able to watch the musical extravaganza live on BBC1 and Radio 2. Organised by Take That singer Gary Barlow, it will showcase the best of pop, rock, classical and musical theatre from each decade of the monarch’s 60-year reign