Anti-pop star Charli xcx is a British singer/songwriter who reimagined mainstream pop conventions with a cultivated irreverence. Sonically, she prefers serrated edges to manufactured gloss—“Vroom Vroom” borrows grime's choppy rhythms—and her big, anthemic choruses echo punk's fight-song catharsis, as in the ode to teen rebellion “Break the Rules” and the mega-smash kiss-off with Swedish duo Icona Pop “I Love It”. She's also devastatingly wry, like in “You (Ha Ha Ha),” an electro-psych tune that opts for swaggering told-ya-so schadenfreude rather than basic vengeance.