Finally an answer to the lingering question: What will life be like when theater geeks and show-tune queens rule the world? Let us extrapolate from Stagedoor Manor’s microcosm. At first glance it resembles any special-interest summer camp, except perhaps for the teens’ propensity to burst spontaneously into song and dance. In this egalitarian utopia, every camper is cast into at least one of 12 full-fledged productions staged in three short weeks each summer. An elite few, however, engage in a cutthroat competition for the chance to appear in a musical revue at a neighboring Borscht Belt resort. Documentarian Alexandra Shiva’s cameras miss the moment some of the alpha divas cross the line, but the overwrought counselors make it sound like a showbiz Lord of the Flies. Shiva has a sensitive eye for rarefied outcasts (her debut doc: Bombay Eunuchs): A staffer underestimates that 70 percent of Stagedoor‘s boys are gay, and the stage parents recount horror stories of their kids’ inability to function outside this sheltered social experiment. One can’t help wondering what sort of life awaits them once the curtain falls, the applause dies down, and the anonymous stars are bused back into the real world .