Myleene Klass and Nick Knowles host the search for Britain's best choir. With a guaranteed place in the knockout stages for the choir who give the standout performance, five of the final 15 choirs do battle in the second studio heat. Judges Russell Watson, Sharon D Clarke and Suzi Digby decide which choirs have the passion, power and performance to progress in the competition where one group will be crowned as Britain's best choir.