Canadian punkers Sum 41 [ tickets ]--Deryck Whibley (vocals, guitar), Dave "Brownsound" Baksh (vocals, guitar), Cone McCaslin (bass), and Steve Jocz (drums)--smart-alecked their way into the mainstream with 2001's "All Killer No Filler." On the follow-up, "Does This Look Infected?," the band got more lyrically serious on tracks like "The Hell Song" and "Still Waiting."

The even-more solemn origins of "Chuck" come from the band's trip to the Democratic Republic of Congo, where they participated in a documentary about the nation's longstanding civil war. Although they supposedly arrived during a cease-fire, they found themselves in the midst of gunfire and bombs.

The result: one somber punk record. The Sums have a knack for worthy melodies and tight musicianship, but one wonders if they'll be allowed to step into maturity. The metallic "We're All To Blame" ponders our "culture of fear" and our penchant for "supersizing our tragedy." "No Reason" is a searing rocker that groans, "the future's not so bright." But there's resolve after the opening acoustic guitar of "Some Say," as Whibley urges listeners to "think before you make up your mind."

Blink-182 admirably stretched on their latest, to mixed fanfare. Green Day wrote a punk-opera with "American Idiot." If this is Sum 41's attempt at leaving adolescence behind, they're certainly doing it for the right reasons.