Plot: World-renowned composer Andrew Lloyd Webber, award-winning singer-songwriter Gary Barlow and choirmaster Gareth Malone - accompanied by members of the London Youth Choir - are set to perform a very special version of Sing, in honour of the Queen’s long association with the Royal Variety Performance . Other music acts include disco sensations Nile Rodgers & Chic, chart-topper George Ezra, multi award-winner Ellie Goulding, Eurovision star Sam Ryder, and popstar Becky Hill