Darcey Bussell gives her farewell performance with the Royal Ballet at the Royal Opera House, Covent Garden. Britain's most famous ballerina of the current generation takes her final steps in Mahler's Song of the Earth, choreographed by Kenneth MacMillan. Presenter Martha Kearney looks back over Darcey's highly successful 20 year dancing career. She's joined backstage at the Paul Hamlyn Hall by Jonathan Cope, one of Darcey's dancing partners.