Fall Out Boy’s second album isn’t so much a reinvention of their sound—that would come later in their career—but it is a significant refinement. The core elements the band explored on 2003’s Take This to Your Grave remain intact—a Zeitgeist-seizing melange of emo, pop, and punk rock; lyrics that are ruthlessly self-deprecating, achingly self-aware, and dripping in melodrama; interminably long song titles such as “I’ve Got a Dark Alley and a Bad Idea That Says You Should Shut Your Mouth (Summer Song).” But under the watch of producer Neal Avron (New Found Glory), the band’s major-label debut speaks of a group growing more musically daring and melodically intricate. It’s telling that when first approached about producing the record Avron declined, stating he didn’t think the Chicago quartet had the songs. When an Island Def Jam A&R representative later sent him recordings of two new demos, “Sugar, We’re Goin Down” and “Dance, Dance,” he changed his mind. The former builds from a surging, slow-building chug into an arena-filling chorus, while the latter takes a more funk and R&B-influenced approach. Both would go on to become hits, ensuring the group’s days as a cult act were numbered. To listen to the album’s lyrics is to get a peek into the mind of bassist/lyricist Pete Wentz, his insecurities laid bare. By the end of “Our Lawyer Made Us Change the Name of This Song So We Wouldn’t Get Sued” he’s cast the band as “liars” and “bad news” while admitting “We will leave you high and dry/It’s not worth the hearing you’ll lose.” Self-doubt makes an appearance on “Of All the Gin Joints In All the World” (“You only hold me up like this/’Cause you don’t know who I really am”), while self-deprecation and self-awareness collide in “Get Busy Living or Get Busy Dying (Do Your Part to Save the Scene and Stop Going to Shows)” (“All us boys are just screaming into microphones for attention”). A voyeuristic twist on sexual obsession propels “Sugar, We’re Goin Down” (“Oh, don’t mind me, I’m watching you two from the closet/Wishing to be the friction in your jeans”), but it’s the oddly upbeat “7 Minutes In Heaven (Atavan Halen)” in which Wentz truly lays his soul bare, the song inspired by a suicide attempt and his battles with depression (“I’m having another episode/I just need a stronger dose”). From Under the Cork Tree’s mix of melodrama and melody made them poster boys for a scene that, along with contemporaries My Chemical Romance and Paramore, was on the verge of exploding. Their lives would never be the same again.