Following the extraordinary phenomenon that came from his choir of Military Wives, choirmaster Gareth Malone wants to get staff in some of Britain's busiest workplaces singing while they work. Travelling across the country, he sets out to create four unique choirs in four very different organisations which will then sing head-to-head in a contest to find the best workplace choir. At 'Lewisham Hospital', Gareth has to engage with over 200 departments on 14 sites, drawing on kitchen porters, nurses, surgeons and office workers, as he narrows down 120 auditions to just 30 voices who can sing as one. In Bristol, in 'The Royal Mail' with 3,000 staff, Gareth finds that an ever-changing work environment leads to dissent, but also to a special kind of unity. Landing at 'Manchester Airport' Gareth finds that divisions between landside and airside allows him to bring workers together like never before, uncovering voices that are ready to take flight. And finally Gareth is sent to Coventry where he will draw on the 5,000 staff at 'Severn Trent Water' from office staff to work gangs in search of a choir that can perform at competition level. Singing before their fellow staff and select judges, the choirs must practice, evolve and fuse their voices into a seamless thing of beauty as they compete to become the best workplace choir at the International Eisteddfod in Llangollen. It's a competition with heart where everyday people, the day-to-day workers that put the Great in Britain, find their voice as they 'Sing While You Work'.