Over the years we’ve enjoyed the likes of Pop Idol, Fame Academy, and more recently Britain’s Got Talent, The X Factor and The Voice UK. Now, there’s a new kid on the block in the form of BBC Saturday night series All Together Now, described as a talent show with a twist.

The quirky format sees a range of singers take to the stage to perform in front of The 100 – a panel of music experts and performers from all over the UK, which will be headed up by former Spice Girl Geri Horner (better known as Geri Halliwell).

Comedian Rob Beckett joins her to present the show, collecting compliments and critique from Geri and the crowd after each song.

At the end of each episode, just two contestants take a step closer to the grand final – and the whopping £50,000 prize pot.

There are no turning chairs or golden buzzers in this show, though. It’s the job of the contestants to simply impress The 100 and get them on their feet and singing along.

“If you like Take Me Out, you’ll love this show,” laughs Geri, 45, referring to the light-hearted ITV dating show, as she chats to us ahead of the first episode tonight.

“It’s more about the characters who are chosen. We, in The 100, get up, sing and turn our lights on if we like the song. If we don’t, we won’t.”

The 100 – a unique bunch of musical experts, including a rapper, a reverend, a choirmaster and opera singers – are an entertaining bunch, too, explains Geri.

“Lily, who sits next to me, gets up for everyone,” she says.

“On the other side you’ve got a fabulous villain. He’s a bit like Jafar from Aladdin and won’t stand for anyone.”

Episode one gets the party started with contestants singing Lionel Richie and Tina Turner classics, a hit by Ariana Grande and West End floor-fillers All That Jazz and One Night Only.

And stay tuned for the jaw-dropping mash-up of opera and rock ’n’ roll. Geri reflects that it’s a nerve-wracking business, taking to the stage.

As each contestant starts singing, The 100 have exactly 30 seconds to wait before they can make a move. Sometimes, says Geri, people don’t stand until the end.

“Maybe they’re just enjoying the performance, or maybe they’re not feeling it. It can be very unnerving.”

In the 90s, Geri was part of the biggest-selling girl band of all time, pumping out hit after hit with the Spice Girls. When they split in 1998, she went on to release three solo albums and four number one singles.

So, it’s fair to say that she knows a thing or two about the industry and how to handle criticism – not that she’s been too tough on the show’s performers.

“I have the courage to speak the truth, but I try to be kind as well,” she confesses.

“It’s not easy to perform in front of strangers. Luckily this show is honest and encouraging.” So what makes Geri dance and sing along?

“It’s quite extraordinary what makes you get up. I like anything from a really cool rap song to the soundtrack from [kids’ animated film] Frozen.”

As mum to daughter Bluebell, 11 (with her former partner, screenwriter Sacha Gervasi), and son Montague – who she welcomed last January, with her husband, Red Bull Formula One team chief Christian Horner – there are no doubt plenty of children’s songs played in Geri’s house.

Between caring for the kids, the busy star has found time to present daytime TV shows such as This Morning and The One Show, launch a swimwear collection with Next and even pen a children’s book series called Ugenia Lavender.

Over Christmas, the star also joined Martine McCutcheon and Professor Green in the kitchen to lend a hand, whipping up dishes for unsung public heroes on Gordon, Gino and Fred’s Great Christmas Roast.

What we really, really want is a Spice Girls reunion, though. It’s rumoured that Posh, Sporty, Scary, Baby and Ginger will make a comeback this year, so Geri will have to find time in her busy diary to revive that girl power.

She is reluctant to be drawn on the subject, however, and, for now, her focus is solely on All Together Now.

“This is in a different lane to the other singing shows. It’s like comparing The Muppet Show with The Bourne Identity,” she says.

“This is more than a music show. People and music come together. You’ll love it.”