Emo can be a gross mix of self-absorption and media savvy. Which is what makes the naiveté of these tortured Tennesseans so likable. On 2007’s platinum Riot!, they seemed to behaving actual fun playing their sharp, sheer mall punk. Produced by Rob Cavallo, the follow-up has a whiff of Important Rock Statement: Singer Hayley Williams blazes TV preachers, does some career-oriented stock-taking (“Looking Up”) and even tries an acoustic ballad. But someof the sweeping moments blunt the band’s fresh-faced immediacy —as if the cute kids from the sticks have had a hard time turning pro.