The Naked Choir with Gareth Malone BBC2, 9pm
New series. Gareth begins the search for Britain's most entertaining amateur singing group, who must perform a capella - without instruments or backing tracks. The first four groups sing to stay in the contest, as they aim to impress before a live audience and jury of a capella experts, who will have the final say on who goes through and who is eliminated. A London community choir, an Essex Gospel group, six Southampton students and a group of female barbershoppers from Portsmouth are those first into the spotlight.