The children face the public for the first time, performing on an open-top bus in the town centre. Gareth wants their performance to attract an audience of passers-by. They are all going to struggle, but perhaps none more so than the soloist, local girl Molly. Molly has been bullied in the past and it has left her confidence at zero. To help Molly, and all the children, find their inner Leona, Gareth has brought onboard EastEnders star Ricky Norwood. Ricky wants the group to act out the song and really connect with the lyrics. Also paying the children a visit are a group who know a thing or two about putting power into a performance – the Leeds Youth Opera.

Gareth wants to encourage the group to leave their cares behind and focus on how performing a song can change the way you feel – but he may have his work cut out convincing this group that the song Jailhouse Rock is fun to perform. Also, Gareth decides that to really get into this new style, they should start dancing as well as singing, so Strictly Come Dancing duo Ali Bastian and Robin Windsor turn up to give a master class.

This episode's soloist, Namibian-born Charlize, is particularly reluctant to embrace rock and roll, and finds the tongue-twister lyrics difficult to get her head around. But she and the rest of the group must learn the complicated words in time for the performance. So far the group have only performed to each other, and a few passers-by on the street. This time the stakes are raised as they sing in front of professional performers, who are experts in rock and roll.

To get his group writing a meaningful song of their own, Gareth suggests drawing on their personal experiences and it does not take long for a common theme to arise – being bullied. By focusing on feelings they have all shared, Gareth hopes their spirit will inspire others, because their final performance will reach thousands as they will be singing live on BBC London radio.

Local lad Taylor has his own concerns about singing to London listeners, as he has been teased in the past for his love of singing and he has started to believe what he has been told – that singing high notes is girly. So Gareth has a struggle on his hands to convince Taylor to just go for it.

To help prepare for such a major performance, the group are joined on the bus by a special celebrity guest mentor, who knows a thing or two about singing for thousands of people – former Spice Girl Melanie C.

The girls are trying to channel the feistiest female group ever, the Spice Girls, by performing their track Spice Up Your Life, whilst the boys are taking on classic anthem Never Forget by enduring boy band Take That. Both groups must work together to beat their rivals, and beat their own nerves.

Will the prospect of performing to real girl band Wonderland and boy band Encore, as well as a record company executive, be enough of an incentive to get both groups working well together? In this case, No. The group faced the challenges of gender issues, veganism and gun control.

With two bands come two soloists. Joan is taking the lead for the girls, but she does not like being the centre of attention and cannot even bring herself to join her mum's choir. Gareth hopes that by making her confront her fear and sing for them, she will find the courage to become a member. The boys' soloist is Mohammed, whose family is used to seeing him excel academically, but he has never shown them his creative side – now that is all about to change.

Can both Joan and Mohammed take strength from their personal challenges? And which will lead their group to victory? It is the Big Performance battle of the bands.

Parts cut from show: GMMAZ (Greater Manchester Music Action Zone) performance of their single "Drop That Funky Bass" to the group.

to the stage. They enjoy having their make-up being put on and getting dressed in jazzy costumes.