Choirmaster Gareth Malone is back. He thinks the Military Wives are the perfect choice to launch the nation's centenary commemorations of the outbreak of World War I, and he pulls together a new Military Wives super-choir to stage a very special prom in association with the National Theatre's War Horse team.

It is three years since Gareth formed the first Military Wives choir, and since then the organisation has mushroomed with over 80 choirs and 2,000 members around the globe.

In this episode, Gareth works the wives harder than ever as they prepare to share the stage of the Royal Albert Hall with some of the world's top professional musicians on 3 August - the eve of the day Britain entered World War I.

The wives meet the National Theatre's War Horse team who they will perform alongside, and the planned repertoire forces the wives to confront their own vulnerability. One of the serving wives makes the momentous decision to leave the Armed Forces.

The episode culminates in Gareth and his 100-strong amateur choir giving the most professional and emotionally engaged performance at the BBC Proms. Show less