A decade ago, when reality TV show Popstars: The Rivals pitted Girls Aloud against favourites One True Voice, you wouldn't have put money on the female underdogs making it past the series' end. More than 10 years later, their boyband rivals are long forgotten, while Girls Aloud are part of the pop landscape. Aided no doubt by writing-production team Xenomania's electronic pop constructions, they have almost reached the Spice Girls' level of ubiquity. Their massive audience unites middle-aged and gay couples, families, tots and teens and chin-stroking pop theorists, the latter perhaps not among those waving foam hands and wearing Cheryl Cole masks.
Girls Aloud's Ten: The Hits reunion tour gives the screaming crowd exactly what they want: 20 consecutive top 10 smashes, including four No 1s, in near-chronological order, from 2002's edgy electronic Sound of the Underground to the recent Something New.
The Girls' first outing in four years is a bigger-budget show than usual, with suspended aerial platforms, a stage in the middle of the audience, tiny dresses, dancers, chairs rising from the floor, and a particularly hilarious moment when Nicola Roberts emerges from a trapdoor wearing a giant Native American headdress and simply cannot keep a straight face.
For all the high art pretensions – the video montage of the five in full New Romantic makeup, Cole's newly rose-tattooed back, Nadine Coyle's strict perma-pout or the traces of David Bowie's Jean Genie in Biology – the Saturday night/tottering girl-next-door aspect is crucial to their appeal. It's there in the uncomfortably tight corsets, bizarre backdrops showing sushi, and the bit in Untouchable where the live band suddenly sound like they're playing in a working men's club in Preston.
And yet, The Show simmers with sarcasm and feminism; red-haired Roberts is a pure, soulful vocalist; and in Something Kinda Ooooh, The Promise, Call the Shots, Can't Speak French and the rest, they must have the finest run of girl group singles since Bananarama or the Supremes.
With the girls now pushing 30, this tour has the added frisson of nostalgia and emotion. As films of the teenage Girls Aloud show them looking wide-eyed and vulnerable, their Abbaesque version of the Pretenders' I'll Stand By You transforms into an anthem of togetherness and endurance. There are real tears from Cole and Sarah Harding, and a group hug so palpably genuine that you wouldn't bet against them doing this in another 10 years' time.
• What have you been to see lately? Tell us about it on Twitter using #GdnGig
