Subtitled ''a soap opera,'' this clever modernization of Heinrich Marschner's 1827 opera in which vampirism has inevitably evolved into big business is wildly entertaining and unexpectedly erotic, a cornucopia of camp and kitsch, shot with the ceaseless energy of a music video. Even people who don't care about opera will be won over by The Vampyr: When the characters sing words like ''Oh, s---!'' in recitative, all of this sounds hilariously, perfectly at home. A-

