No one does the droll, urbane, embittered-romantic shtick better than Magnetic Fields auteur Stephin Merritt. On this overdue follow-up to 1999's ''69 Love Songs,'' he again manages to transform the caustic into something transcendent, even jaunty (exquisite swipes like ''I Don't Believe You'') with I. But sometimes his lyrics are better than his melodies (''I Wish I Had an Evil Twin''), and too often even his happy songs sound dreary.

