The Spark Is Still There As theme parties go, it was a spirited hoedown, guests miming the moves and the scintillant garb of their favorite performers, Prince, that living avatar of "80s glam, and the pop legend Michael Jackson. The scene, an annual dance-off held the other week at Highline Ballroom in Manhattan, teemed with Prince lookalikes dressed in his gaudy signatures: high heels and ruffles, flares and trousers with their backsides sheared away. The night reached its hectic climax as audience members clambered to the stage to perform their own renditions of Jackson's "Thriller." As versed in the look as they were in the dance, they writhed uninhibitedly, wearing funky fedoras, white socks and loafers, raising white sequined gloves, and flaunting the glittery band jackets that Jackson made his own.