Get quizzical: can you recognise these a cappella versions of BBC TWO shows?

A cappela group The Sons of Pitches as seen on The Naked Choir with Gareth Malone tackle theme tunes to three of the BBC's favourite shows. Can you guess which ones they are?

l-r: Joe Hinds (nicknamed Hindsy), Joe Novelli (nicknamed Novs), Joe Belham (nicknamed Bels), Mide Adenaike and Josh Mallett. Other member Jamie Hughes is missing from this line up.