Katy Perry

A Californian diva with a sense of humour is a rare thing indeed, but Mrs Brand is anything but orthodox

The Odyssey Arena stage is done up like Willy Wonka’s Chocolate Factory meets Alice in Wonderland, with candy cane handrails, bubblegum clouds and dancers dressed as everything from Elvis to an oversized purple kitten. Yes, Katy Perry’s in town, and the bizarre-o-meter is off the chart.

After a lavish video intro featuring our Perry being tormented by a butcher (it’s a long story), the singer appears, the twee-est, most girly girl this side of Essex. ‘Who cares if it’s Monday?’ she squeals. ‘Let’s pretend it’s Friday!’

The sold-out crowd on this wet and windy Belfast evening respond by shrieking their damp little heads off and holding their camera phones aloft to film the unfolding spectacle.

It’s certainly the strangest and most entertaining pop show this writer has seen, with flying mimes, giant gingerbread men and a talking one-armed bandit named Slot ('I said, "S-L-O-T,"' quips Perry).

There’s a dark undercurrent to proceedings, with Perry often coming across like Alice Cooper’s snotty kid sister – or at least his snotty granddaughter.

Winningly, the extravaganza reflects the vocalist’s unique personality, rather than just piling on more identikit walkways and podiums. I doubt there’ll be anyone handing out giant hash brownies or waving peacock feathers at Britney Spears's concert the following evening, for instance.

Throughout the gig, Perry – who turns 27 the following day – variously refers to herself as ‘a nerd’, ‘strange’ and having ‘never been normal’. Her audience laps it up, and for one male fan his dreams come true when Perry brings him on stage to kiss her.

Perry makes the lad, named Keith, take his top off, and grabs his pec. ‘It’s my birthday and I can have anything I want,’ purrs the diva – before a roadie informs her that hubbie Russell Brand has just arrived, and Keith is unceremoniously booted off stage. (Brand isn’t in the building, though several roadies wearing masks of him are. It’s that kind of show.)

The music itself is relentlessly upbeat, a stomping, 80s-influenced concoction as sickly and sugary as the surroundings. Still, as the guitars buzz and the drums thump away, you can see how Perry was able to do the punk-friendly Warped tour, or why the likes of Snoop Dogg and Kanye West are queuing up to work with her.

'Teenage Dream', ‘I Kissed a Girl’, ‘Hot n cold’ and ‘California Gurls’ are slices of prime pop, and covers of the Strangeloves’ ‘I Want Candy’ and Whitney Houston’s ‘I Wanna Dance with Somebody’ only sweeten the deal.

It’s not all great, of course. Ballad ‘Thinking of You’ is a bit of a dirge, Perry's dancing is strictly amateur-hour and you imagine the precocious star would be a pain in the ass to spend more than five minutes with. 'I'm half-Irish,' she bleats at one point. 'Even though I have black hair, I have ginger roots.'

Yet on stage you can’t take your eyes off her – or ears. Her voice isn't as bad as some reviewers have suggested, and she is at least singing live, as proven when her microphone cuts out and her lips continue to move.

Perry wraps things up by chucking a birthday cake into the crowd, spraying them with icing and dropping a load of confetti and beach balls on them, before disappearing with a flash of the devil horns. Even tarred, feathered and bruised, Perry’s fans still love her – and she has made at least one new convert tonight.