“There’s not much I wouldn’t let you whisper in my ear,” coos Jessica Lea Mayfield on her second album. At 21, Mayfield looks like an ingénue but sings like a worldly-wise veteran, picking apart relationships with the sly eroticism of someone who’s lived a little. Producer Dan Auerbach (of the Black Keys) gives Mayfield’s confessions a darker hue, laying on tremolo guitar while nudging the noirish country songs toward British Invasion pop (“Nervous Lonely Night”), among other genres. But the most compelling sound on Tell Me is Mayfield’s languid drawl. “My brain is speeding faster than my mouth can move,” she sings. It’s true — but with songs this seductive, that’s no problem.