A far cry from her ska-beat debut, “The Fear” is Lily Allen’s first single off her upcoming record, It’s Not Me, It’s You. The wit is still in fine form as the UK singer spouts off cleverly mocking lines about oblivious, spend-purge-spend socialites—”I am a weapon of mass-consumption,” “I’m not a saint, and I’m not a sinner. But everything’s cool, as long as I’m getting thinner”—but with slick production and soft-focus vocals, the track loses the bratty edge that made Allen’s best work (“Smile,” “Alfie”) so memorable. So the comeback begins?