At two A.M. on a Monday in Ibiza, Seth Troxler was spinning a remixed Gloria Gaynor song amid the red-tinted interiors of the DC-10 nightclub. The popular Detroit D.J. was performing at the weekly Circoloco party, where the dance floor is always filled to capacity with beefy men in tattoo sleeves, elegant blondes in Louboutin booties, drugged-up financiers, and aspiring D.J.’s.

Outside, crowds smoked cigarettes and talked about nothing while planes angling toward Ibiza Airport, a two-minute drive away, soared overhead.