Duffy shot to stardom in the U.K. with a variation on a beloved brand: Amy Winehouse without the train wreck. She’s just what Brits like in an R&B singer — a pretty girl who loves stately soul ballads. Her second album is tasteful, well-made and kind of dull. Duffy has a fine voice, smoky and touched with grit, and she opens with “My Boy,” which gets funky oomph from guest backup band the Roots. But where Winehouse’s singing grabs you by the lapels, Duffy’s feels affectless. Her ballads and neo-disco songs are steeped in lovelorn melodrama, but her bland persona doesn’t give the storms life. You’re left with saggy stylistic gestures that seem to drag on, endlessly.