The girls are in scraps of bikini, their upper bodies groaning with silicone, and they're gyrating beside musclebound men who can match them inch-for-inch with their protruding pectorals. Meanwhile, little Annie "Mac" MacManus stands amidst this mass of beautiful people, choreographing its movement by means of the mix of eclectic music that she calls her "mash up".
She is under the Miami sun, looking out across Ocean Drive at the multiple shades of blue where clear skies merge with the Atlantic. At her back is the swimming pool of the Surfcomber Hotel, a scene of flesh and frolicking. At Annie's side are various figures of DJing repute; Pete Tong, Goldie, Mark Ronson.
Yet, not too long ago, she was living a quite different existence. Stuck in the nondescript Hampshire town of Farnborough, working in a supermarket and studying for a post-graduate qualification in radio, the highlight of her week was shopping at a car-boot sale in a multi-storey car park.
The tale of how she went from the then to the now, standing before the gym-honed hordes in her red-rimmed Diesel sunglasses, matching black-and-red dress and with a chunky hip-hop gold necklace (it's actually the strap of a Marc Jacobs handbag) hanging off her shoulders, should be an inspiration to every young media wannabe.
Not that her latest experience is one of unbridled joy. The prospect of broadcasting live on BBC Radio 1, while deejaying for a hard-to-please crowd at Miami's famed Winter Music Conference, shredded the 29-year-old's nerves. As she watched Tong rocking the crowd, prior to her own performance, she was close to tears. "It took me half an hour to stop shaking, I was absolutely bricking it."
Unlike Tong, Annie Mac is not a big name on the international DJ circuit. And unlike him, she was not planning to give the Miami crowd the mix of house classics they wanted but rather to broaden their musical horizons. "When you've got something that's going perfectly and you know you are going to challenge people, well, not everybody is going to be happy. It was hugely intimidating. Over here people don't know who I am and you just want people to like you," she says, adding in an imploring voice: "Please dance, please clap."
Afterwards she is honest enough to admit that "not everyone liked the music" but, from a neutral's perspective, the partying slowed not a jot as the rising star of the Radio 1 schedule strayed into new territories, with flavourings of hip-hop, indie rock and punk.
Annie Mac is a pivotal figure at Radio 1. Her innovative Friday night show Annie Mac's Mash Up perfectly fits the network's remit of breaking new British music. In addition, she is standing in for Sara Cox on Saturdays and Sundays while the latter is on maternity leave, and was hand-picked as a face of the BBC multimedia Switch project, which is aimed at engaging with teenagers and includes the BBC2 music show Sound, which she presents with Nick Grimshaw.
She has worked her way up the greasy pole, having joined the station as a broadcast assistant to Steve Lamacq in 2002 at the age of 23. "I had given myself a little deadline: I wanted to be on Radio 1 by the time I was 26."
A Dubliner who – in between going clubbing – studied English literature at Queen's University, Belfast, MacManus decided she wanted to work in radio in the final year of her degree. After her "miserable" year in Farnborough ("it's still the biggest culture-shock I've ever experienced in my life"), she moved to London to live with her brother and the other members of his band, The Crimea.
Work experience at the band's V2 record label led to a succession of stepping-stone jobs at Pam Ghuneim's record plugging company The Hubb, an ill-fated online radio station called Net FM, which was aimed at men working in IT, and the Student Broadcast Network, where she engineered sessions with bands and produced and presented her own music show. "There was a period of six months when I worked seven days a week. I would go over to [north London music venue] the Barfly in my lunch break to interview the bands and then come back to work again."
Ghuneim helped persuade Radio 1 to give MacManus a break. Her first voicing was for an "ident" for a punk-rock show, because the producer liked the way MacManus, with her Dublin accent, said "ponk". Nowadays, her tones are so hybrid that she gets mistaken for a Bristolian. "I get so crucified when I go home because of my English accent," she says.
MacManus landed her own show after making a demo as a stand-in for presenter Mary Anne Hobbs, one of her broadcasting heroes. The first edition of 'The Annie Mac Show' was broadcast on 29 July 2004. "It was 11 days after my 26th birthday. I was late."
As she has perfected her broadcasting so she has become in-demand to perform at clubs. "I was pretty much thrown into the deep end in terms of club DJing," she admits. "I made my mistakes in public and was completely traumatised for it but I learned not to worry about it and I got better. I feel I've got something to give now but back then, my God! – I used to find it really difficult. It's so ironic that I broadcast to half a million people and it doesn't nerve me in the slightest but when you go out it's a physical performance as well as a reflection of your personality."
But while she is now being asked to do a US tour, the words of the Radio 1 controller Andy Parfitt, counselling against his station being "too cool for school", ring in her ears.
"If you work in music 24-7 it's the norm to know what record labels people are on but it's important to remember that most people don't care, they probably don't know what a remix is," says MacManus.
"Over the years I've had to become very careful to remember to be normal and not presume that people know stuff. The Mash Up is really conscious of that. I know I have a big old pop sensibility as well as liking underground records. I'm not afraid to play Britney Spears alongside a drum'n'bass record."
So Annie Mac strives to stay normal but, as she performs in Miami, the view is anything but. "I can see a lot of fake breasts, I can see a lot of muscles," she tells her crowd and the listeners back home. "It looks pretty good!"
Annie Mac presents 'Sound' on BBC Two every Saturday at 12pm as part of BBC Switch. She broadcasts on Radio 1 on Fridays 9-11pm and on Saturdays and Sundays 1pm-4pm.