James McCourt's operaphiliac fairy tale of the ""diva oltrano of the century,"" her fanatic devots, her Sicilian rival and her happily-ever-after love affair is as rich, decorative and preposterous as a tea tray of fancy iced pastries. Mawrdew Czgowchwz (call her Gorgeous) is the darling of the soignee sybarites of the Old Met -- a Busby Berkeley cast of socialites, doxies and stage door suitors. McCourt keeps his pastiche of the opera scene of the '40's together between ovations and crises with the frothy wit of Gotham's gossips, critics, snoops and champions, who are all as smart and fashionable and elegant as Moet champagne and beluga caviar. Even a hex engineered by an invidious Grand Street witch cannot halt Mawrdew's progress toward perfection but only leads to the revelation of her true identity as one of the Hibernian chosen few; come St. Patrick's Day, Mawrdew triumphs again. It's really only extravagant camp, but McCourt's debut has a glitter and stylishness all his own.