Katy Perry, LG Arena, Birmingham

As her rendition of “Double Rainbow”, from recent album Prism, draws to end, Katy Perry announces into her microphone that “It was the music that brought you here! You like the costumes and lights but the music brought you here!” The funny thing is that actually the music is the least of things in the Katy Perry live spectacular.

The stage set is loaded with trap doors, moving platforms, dry ice, lights, lazers, a troop of dancers in day-glo costumes that bring more than a sniff of Alice in Wonderland to the proceedings but we are four songs into her set before we see anyone with a musical instrument.

Katy Perry knows her audience though and gives them exactly what they want. She may have been given the accolade of “World’s sexiest woman” by numerous men’s magazines but actually her image is more one of knowing older sister to the hordes of teenage girls who press forward with their mobile phones held up to film their idol. This is reinforced by references to “being out on a school night” and the advertising bombardment of various Katy Perry branded products that appear on the LG Arena’s huge screens before she takes to the stage.

The show was one of many parts, much like acts in a play, each going under names such as “Prismatic”, “Egyptian” and “Cat-Oure” with costume and set changes for each. Hyper-active dancers spun, jumped and flew around the stage on trapeze wires, while musicians came and went. The songs, however, were all pretty much of a type. Bombastic hymns to self-reflection and self-improvement from her Prism album were punctuated by “I kissed a girl”, “Hot ‘n’ Cold” and other worldwide hits from her One of the Boys and Teenage Dream albums. All were characterised by a foghorn voice that seemingly doesn’t do subtlety. That said, it was totally suited to her audience of young girls hopped up on fizzy drinks and fast food and decked out in garb proclaiming their love for their heroine.

Towards the end of the show, as the music began to flag after yet another short break for yet another costume change, Katy finally brought out the big guns. Speeding through hit after hit with “Teenage Dream”, “California Gurls” and recent single “Birthday” to the fore, she even dragged one of the relatively few guys from the audience to sit on a birthday throne to be serenaded. She returned once more for further foghorn singing and an encore of “Firework” but by this time significant numbers from her audience was already trudging towards the exits – but that’s the risk you run of playing a two hour show to barn-load of school kids who have got to get up early the next morning.