They may have been assembled for a reality-television programme but after six hit-strewn years, Girls Aloud are a delightful part of our pop DNA. Live, though, before an audience of gay men, small children and — safely kept in a box — Cheryl Cole’s temptation-prone footballer husband, Ashley, they remain a distinctly mixed and strangely chaste proposition.

At their finest, they were interchangeable pop goddesses, whether dangling from the ceiling like chav cherubs at the start, sauntering down a walkway to the stage in the centre of the crowd singing Whole Lotta History dressed as Opal Fruits or pounding out the heroically insistent Biology and Fling, the glorious places where gay disco meets S Club 7. And that Cole surreally claimed “it’s every artist’s dream to play the O2”, that Sarah Harding’s disastrous Einstein hairdo was a masterclass in how not to coiffure and that they obligingly plugged their sponsors only made them seem more human.

Yet there were more smoke and mirrors than a reflecting cigarette factory. In a set too heavily based on their current album Tangled Up (not even Girls Aloud fans attend Girls Aloud concerts to hear new songs), their voices, understandably breathless between songs after one punishing dance routine piled upon another, were miraculously turbo-charged and pristine each time the music began.

More disturbingly, the video screens rendered these five shapely women grotesquely stick-thin.