Gareth Malone launches his exciting singing contest to find Britain's most entertaining amateur choir.

This week, Gareth is looking for a choir to represent Scotland and the north of England, in a tour that takes him from the rugged beauty of the Scottish Highlands to the rolling hills of the Peak District. From the hundreds who applied, the groups Gareth has chosen to audition include a cancer care choir from Manchester, a troupe of singing mums in Durham, a bluff bunch of Yorkshire pensioners and some soulful singers in Edinburgh. All are hoping to secure a place in a sing-off that could put them through to the national stages of the contest, but who will Gareth choose? And will his expert advice and tuition be enough to help them pull off a performance in their own home town, designed to get them match fit for the later stages of the competition?

This week, Gareth is on home turf as he scours the south west of England for a third regional champion to put through to his nationwide contest. Pit stops include hay barns, harbours and a high tea, on an audition tour that features a Bristol sea shanty band, a cake-loving WI group, a Guernsey church choir and some tuneful young farmers from Devon.

To top it all, Gareth umpires a Pitch Perfect-style song battle between Exeter University's two top a cappella acts. But who from among these hopefuls will Gareth select for the sing-off? Success at this sing-off will secure a place in the national stages of the competition, but also comes with a challenge - ahead of the national contest, the winning choir must work with Gareth to pull off a performance in their home town.