A plethora of celebrity guests join Alan for his two-hour extravaganza in various guises, taking part in sketches and ridiculous games. Plus there's a host of top musical performances and audience participation in the studio. Alan's guests include David Walliams, Justin Bieber, The Saturdays, the cast of Made in Chelsea, Amy Macdonald, Carol Vorderman, Paddy McGuinness, Dr Christian Jessen and Rizzle Kicks who also perform their summer anthem, Mama do the Hump.