Gareth's eight novice singers have been stretched to their limits by a gruelling rehearsal schedule amid their own personal challenges, including a breast cancer diagnosis and a recent bereavement. Now, they put on a glorious performance alongside the BBC National Orchestra, the Chorus of Wales and four leading professional soloists at Cardiff's Llandaff Cathedral.

As an extra surprise, one of Gareth's new singers, Rosie, is offered the chance to perform an inspiring solo piece.

Gareth has taken on the ambitious task of working with eight raw but talented individuals who've never tackled anything quite like Handel's monumental Messiah. Thrown in at the deep end, each intricate chorus of the hundreds-of-pages-long score presents a fresh challenge for his novice group. So far, their journey has been within their small group of eight. However, they're on the verge of a significant step: soon, they'll be singing alongside the professionals – the BBC National Orchestra of Wales and Chorus of Wales.

At the beginning of this episode, the pressure is already building. While the group tries a brief escape to the coast outside Cardiff, to Penarth Pier, rehearsals continue, but one member is noticeably absent. Foo Seng is feeling the weight of expectation and the complexity of the music. As Gareth's belief in his singers grows, he offers one of them, Rosie, the opportunity to perform a solo piece.

Gareth is continuing a long and significant tradition: using Handel's Messiah to raise money for good causes, this time for BBC Children in Need. He explores this history with a visit to the Foundling Hospital, the very place where it all began 275 years ago, and where librarian Catherine Hogg offers him insight into Handel's lasting impact. Just hours before the performance, the dress rehearsal at Llandaff Cathedral takes a dramatic turn. During the powerful "Thou Shalt Break Them" section of Messiah, something unexpected happens to one of the singers and doctors are called to the scene.

Choirmaster Gareth Malone is taking on an enormous challenge: he's coaching eight people with no experience of classical choral music to sing Handel's Messiah alongside the world-class BBC National Orchestra of Wales and Chorus of Wales, at Cardiff's Llandaff Cathedral, in aid of BBC Children in Need.

In the first episode, he heads to a local cinema on Penarth Pier, with pianist and vocal coach, Jane Samuel. There, they face the important task of going through hundreds of tape auditions of Scarborough Fair to find the best candidates.

After whittling down the applications to the chosen eight - Foo Seng, Nia, Harry, Rosie, Aaron, Ami-Louise, Naomi, and Richard - Gareth meets them in Cardiff for the first rehearsal. All eight have their own personal stories and motivations, including Naomi, who has been diagnosed with secondary breast cancer, and Richard, who recently lost his wife to the disease. All are showing promise. But with only six weeks to go, can Gareth and his new recruits handle the Handel in time for the performance of their lives?