New Jersey rock & roll believers Titus Andronicus get top mileage from a simple idea: baiting hardcore thrust with classic-rock hooks. On their fourth album, they bear down on a 90-minute rock opera in a Quadrophenia vein about growing up, freaking out and coming to unsettled terms. A shaggy chorale, a piano ballad, organ drones and Celtic touches — including a hurtling cover of the Pogues’ “A Pair of Brown Eyes” — provide variety. But the center remains frontman Patrick Stickles’ desperate howl, a mix of Johnny Rotten, Paul Westerberg and Conor Oberst that sounds fittingly trounced by the end. Long may he wail.