Sum 41 have always seemed like blink-182's baby brothers, right down to their nonsensical numbers in the name, so it's only appropriate that they're also attempting to grow up just like blink -- or better still, a bit like blink and a bit like Green Day, who have proven to be the standard-bearers for how latter-day punks can grow a social conscience and become mature, as evidenced by American Idiot.

Sporting a similar-sounding but not as politically potent title in Underclass Hero, Sum 41's fifth studio album extends upon its predecessor Chuck's deliberate attempt at getting serious and relevant, containing just enough garbled commentary and political platitudes to not only give the impression that the bandmembers are saying something beyond their beloved clichés, but to give the impression that they're telling a story, creating an anthem for the "underclass hero," the slacker who can't be labeled as an underachiever because he never attempts to achieve.

The first few songs here -- the fists-in-the-air wannabe anthem title track, the narcissistic self-loathing "Walking Disaster" -- hit as hard as processed pedal distortion can, but Sum 41 (now down to a trio after the departure of guitarist Dave Baksh) soon abandon any larger narrative as they start to stretch out with acoustic guitars, keyboards, and Queen harmonies uncannily reminiscent of My Chemical Romance's more conceptually cohesive The Black Parade.

Despite these flashy accoutrements, Sum 41 don't want to be emo, they don't want to be prog, they don't even aspire to the mock the U2 atmospherics of Angels and Airwaves; they want to be nothing more than pedestrian yet pleasant punk-pop, predictable in every way from their nagging chant-along choruses to their portentous attempts at rewriting "Good Riddance (Time of Your Life)." Like all Sum 41 albums, Underclass Hero is ingratiating enough as background music -- it's hooky enough to have momentum but not enough to linger in the memory -- but they've never sounded quite so toothless and it's all down to this increased ambition.

Now that Deryck Whibley wants to say something important, it's all the more evident that he's not armed with much more than a juvenile sense of melody and a cookie-cutter outlook on the world: when he's railing against his parents or the man at large, he gives no specifics, only platitudes, which only emphasizes that this is prefabricated rebellion, protest music for the branding generation -- kids who make a stand by preferring Pepsi to Coke or Burger King to McDonalds.

Or Sum 41 to blink-182.