The crowd at pop concerts seem to get younger – and tartier – every year.

Take for instance, the teenybopper walking on the stairs at Auckland’s Vector Arena. From the back, she looked all of about 14, and was wearing a skirt the size of a handkerchief, from which almost everyone behind her got a good view up.

Young lady, does your mother know you’re wearing a G-string?

Skirt looker-upper girl gave a glimpse of what the rest of the evening entailed. Even on a school night, the teens – many of which were wearing matching clothes – were out in full force to celebrate the double billing of Rihanna and Chris Brown.

Brown is the kind of good looking brotha that appeals to both 12-year-old boys and 16-year-old girls, who combined to scream in such deafening tones they drowned out a good portion of his first song.

No matter, because what really impressed was the fact that he descended, god-like, from the roof with a team of dancers dressed like ninjas.

They proceeded to rev up the crowd with club favourites (Yo) Excuse Me Miss and With You, which prompted the plenty of girly sobbing.

A group of teens in oversized T-shirts and what looked like bikini bottoms down front nearly fainted when Kiss Kiss came on.

As a nod to the older people in the crowd – like the ones who could actually go to The Lounge later in the night for the after party – Brown also did a quick tribute to Michael Jackson, including a very passable moonwalk.

On an ironic note, Brown got several audience members to come on stage, mostly female – and played Nirvana’s Smells Like Teen Spirit while the teenyboppers went wild.

But it was Rihanna who stole not just the stage, but the night.

She emerged from a moving pedestal dressed in fishnets while belting out Disturbia, and if the chorus of voices for Brown was deafening, the applause for her was a tsunami of sound that relented very little throughout the night.

The show was a combination of burlesque, with girls in corsets – including Rihanna – slinking along the stage, and special effects.

The most spectacular effects were a set of spinning fireworks that showered the stage in sparks. It’s great when musicians say ‘screw you’ to their insurance company.

Disco lights attached to the ceiling gave the entire arena a dance party atmosphere, especially during the obligatory “slow song” part of the concert, during which Rihanna introduced two of her backup singers.

Unlike fellow pop stars like Britney Spears, Rihanna cannot actually sing,and this was one of the few parts of the night which truly showcased her amazing vocals. She crooned out Good Girl Gone Bad, Hate That I Love You – minus Ne-Yo – and Unfaithful, which turned into a crowd sing-a-long.

The biggest shrieks of the night were saved for the end, when she played Please Don’t Stop The Music, complete with fireworks, smoke machines and a blazing finale.

She came back for an encore, which featured Take A Bow and undoubtedly the biggest dance floor song of last year, Umbrella … ella … ella … ella sung partly in conjunction with rumoured boyfriend Brown, who couldn’t resist coming back for another round of teenybopper love.