It is the grand final of Gareth Malone's contest to find the nation's most entertaining amateur a cappella group. Just one more performance stands between the three finalists and the title of series champion. Their last challenge comes with a fiendish twist that poses a cheeky problem for one of the contenders, while one of their rival groups struggles with the demands of life outside the contest and the other goes all out to win with an a cappella country getaway. To emerge triumphant, the groups must compete in front of a thousand-strong audience at London's prestigious KoKo and impress a jury of a cappella experts. Their votes decide who will be crowned the contest winner. Show less