Watching Steps brings to mind George Orwell's image of the future as "a boot stamping on a human face for ever". The band inhabit their own Orwellian pop nightmare: thousands of tiny boots stamp on the floor of Sheffield Arena, screams are louder than missiles and this tour will last longer than many wars. Five years after their creation in one of modern pop's many Frankenstein laboratories, this incredibly successful and slightly sinister ministry of sound are edging ever closer to world domination.

Somewhere among the 15,000 revellers, there exists the one young person who hasn't pestered mummy to shell out for the new hits compilation, and bandmember H - a faintly camp former Butlins redcoat - is determined to find that child. "This is the Gold greatest hits tour to coincide with the Gold album," he explains. Those who resist Steps' calls to dance are poked to their feet by the band's fans, an authoritarian army of glitter-rod-wielding tiny terrors.

Quite why Steps have become so enormous is mystifying. Half their set consists of covers, which only blonde Claire can really sing. They perform to backing tapes, and every time the video camera pans to a Step, it manages to catch the one who isn't singing. Pete Waterman, who signed them, describes the band as "Abba on speed", and the voices (multi-tracked, then multi-tracked again) are slightly high, the beats slightly fast. To an adult, Steps sound like a straining pub jukebox. However, their music obviously touches a certain frequency in a female child's brain that triggers excitement.

As shows go, this one isn't bad, with costume changes, dancers, papier-mache heads, a trapeze and at least one sequence involving plant-pot hats. But the band seem more robotic than fun-loving. In one surreally adult moment, Lee and H allow themselves a joke at the unwitting audience's expense. "Shall we split 'em?" asks H. "Not literally," quips his colleague.

In fact, the band's creators are already planning the difficult shift into a more adult market. Thus, a distinctly nervous Claire introduces Tim Rice's I Know Him So Well, and the AOR horror duly falls flatter than an old balloon. It's hastily back to big plastic disco numbers, explosions of glitter and squealing. Their big brothers won't like it, but the little girls clearly understand.

· Steps play the SECC, Glasgow (0870 040 4000), from tonight until Friday, then tour.