This past December, it was just a little too easy for the local smart alecks to make cracks about Miami Beach regressing into a retirement community for musical has-beens. Kicking off Art Basel was one of the most influential bands of the late Sixties — led by rock's most emulated singer (an adopted local no less) and joined by punk's finest bass player. Too easy. But when Iggy Pop and the Stooges came out full bore, those same cognoscenti knew right away they'd be gnawing on their Grecian Formula-coated words before the night was through. The Asheton brothers thundered through their own classics as Iggy sexily pranced around like a boy one-third his age. Mike Watt, formerly of the Minutemen and a cultural institution in his own right, took over the late Dave Alexander's spot to the delight of all — especially his own. At one point, Iggy welcomed the audience onstage for a couple of songs, and several dozen concertgoers took up the offer to wriggle around, singing "No Fun" and smiling at the irony. The only things that made the evening more brag-worthy were the free admission, the starry sky overhead, and the sand you had to shake out of your boots afterward.