The forces of New York City Opera make a compelling case for Die tote Stadt, Korngold’s lush yet elusive masterpiece. John Alexander meets the formidable demands of Paul with assurance, bringing both passion and grace to the role’s punishing heights. Carol Neblett is an alluring Marie/Marietta, investing the character with mystery and glamor. Julius Rudel leads a finely judged performance, drawing out the many layered textures of Korngold’s score.