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.