SPIN CITY: SUPERSTAR DJS GO VEGAS

A tall, tanned girl in a tiny, light-brown fringed bikini can't stop dancing. Her pneumatic breasts undulate to the beat of explosive drums, synthetic blares, and well-timed drops. She's gyrated her way to the front of the 3,000-strong sun-drenched crowd that has piled into Encore Beach Club, inside the luxe Encore Resort in Las Vegas. Behind her, two tiers of ivory-colored cabanas rim a trio of swimming pools; to her left and right, tables cordoned off by velvet ropes are well stocked with Grey Goose and Patrón on ice. Sandwiched between guys in stylish swim trunks and an array of bronzed females with buff bodies, the girl in the fringes wags two index fingers to rhythms that originated in the brain of the Swedish House Mafia cofounder Sebastian Ingrosso. He stands atop a stage six feet above her, pumping well-inked arms in the air.

Up on the shallow riser dominated by a four-channel mixer as wide and as long as a carry-on suitcase, Ingrosso smiles like he's having more fun than anyone else in the place. With four memory cards plugged in, he pushes dials up and down and twiddles knobs, sending out demented whoops, beats, and bleeps. The 29-year-old dance-music savant downs shots of Jägermeister and coaxes the sweaty crowd to party harder at this start of Memorial Day Weekend, a four-day electronic-music extravaganza at Encore and its parent casino, Wynn Las Vegas, owned by the billionaire gaming mogul Steve Wynn.

Soon Ingrosso is joined by a pair of A-list exes—Reggie Bush (Kim Kardashian's former paramour) and Afrojack (Paris Hilton's recent flame), like Ingrosso a member of the international brotherhood of superstar DJs. They in turn hoist a couple of girls as a roar rises from the crowd and a fresh round of Jäger shots get drained. Afrojack does an enthusiastic shout-out, and Bush basks in the moment. A frequent presence on the Vegas club scene, the Miami Dolphins running back has tried to master the mixer, and he's been heard to joke, "Football is coming to an end and soon I'm going to be DJ'ing."

Hear more from Ingrosso over at Details.com