The Frampton sisters, Meg, 21, and Dia, 18, make teen rock for the iPod Shuffle set, whirling emo, ultra-pop and bad-girl guitar into songs that, just shy of frothy, aim squarely for most-played lists. Their first album ladles on the lovely harmonies, but lyricist Meg’s mind is outside the choir room, somewhere underneath the bleachers. Naturally, exes abound, and tracks like “Monster” — a stitching of unmitigated metal chug and poignantly ethereal vocals — tear a page from the emo-boy diary, scolding the cheaters and the merely luckless with something approaching grandeur. “Rebecca,” a moony, pseudo-literary piano ballad, overreaches, but other experiments — sultry acoustic lark “Cardigan Weather,” reggae-laced “Masterpiece” — come off with mid-career élan. They’re adult to the point of being precocious, but their bewitching power comes from the way they straddle the wholesome and the unchaste.

Download: “Monster,” “Roses”