Last year, in the pages of this very newspaper, a reviewer referred to Williamsburg's Brick Theater as "egalitarian and unpretentious." Them's fightin' words. Michael Gardner, the Brick's coartistic director, responded with a call to arms: "[We are] as self-indulgent and impenetrable as the most oblique and experimental performance organizations in the city." To prove it, he has assembled more than 25 short plays into a month-long "Pretentious Festival," running through July 1. One of the first offerings is Lisa Ferber's Dinner at Precisely Eight-Thirteen, a silly (and, dare I say, totally unpretentious) musical spoof of 1930s drawing- room comedies. Heiress Kitty La Blintz (Moira Stone) throws a party to celebrate the reading of her father's will. In attendance is an Agatha Christieish cast of characters, including publishing magnate Snerdley Jammybottoms (Baz Snider), mystery writer Hedy Highball (Jennifer Houston), and erstwhile playboy Flitney Shropfordshire III (Greg LoProto). What follows is the usual cocktail of love, mistaken identity, and murder, with some Continental philosophy thrown in for good measure. None of the cast can singsome of them have cat-howlingly awful voicesbut they're all hell-bent on entertaining you in the old-fashioned way, and they'll do whatever it takes: fainting, kicking up their heels, shooting each other, and even being pretentious, if they must.