It's too soon to tell whether Schwartz's score for Wicked, which opened Thursday at the Gershwin Theatre, will prove as enduring. But it's safe to say that this is the most complete, and completely satisfying, new musical I've come across in a long time. The triumph is not Schwartz's alone. Adapted from a Gregory Maguire novel, Wicked offers a post-feminist, socially conscious reinterpretation of the story of Oz's Wicked Witch of the West. Though that may sound like a recipe for pretentious pedantry, writer Winnie Holzman, whose TV credits include thirtysomething and My So-Called Life, provides a libretto that juggles winning irreverence with thoughtfulness and heart.