Katie Derham introduces the celebrations live from the Royal Albert Hall as the world's greatest music festival reaches the grand finale of its 121st anniversary year. Tenor Juan Diego Florez and 12 hand-picked opera singers are the star vocalistsin a program which includes popular favorites by Michael Torke, Ralph Vaughan Williams, as well as a performance of Ah! Mes Amis from Daughter of the Regiment.Around the U.K., Proms in the Park audiences in Belfast, Glasgow, Walesand London will join the Royal Albert Hall for a medley of favorites such asGod Save the Queen, arranged byBenjamin Britten. Each of the four parks will also have their moment in the spotlight as they sing different pieces, including Glasgow Green Park's rendition ofThe Skye Boat Song, before the traditional climax of Rule Britannia, Land of Hope and Glory and Jerusalem. The BBC Symphony Orchestra and Chorus and the BBC Singers are conducted bySakari Oramo.