On Infinity on High, Fall Out Boy's first album since hitting the Big (Really Huge) Time, tracks like “Fame < Infamy” and “Don’t You Know Who I Think I Am?” find the band wrestling with topics like sudden fame and celebrity. Bass player and lyricist Pete Wentz’ maturity and insights prove disarming, entertaining, and helpful in writing songs with humor and surprising depth. (Bon mots such as, “Bandwagon's full. Please, catch another,” and “I thought I loved you / but it was just how you looked in the light” threaten to lodge his tongue permanently in his cheek).  Small surprises work to keep things fresh in the band’s familiar emo-pop realm: the metallic guitar barbs on “Thriller,” the sweet “doo doo dooo”s sprinkled like candy all over “This Ain’t a Scene,” and Patrick Stump’s pop croon on “I’m Like a Lawyer” show a willingness to stretch and bend.  Any original fans disappointed by the relatively light, pop feel on “Golden” and “The (After) Life of the Party,” will find solace in the breakneck speed of  “You’re Crashing” and the hint of Bad Religion guitar grandiosity on  “Bang the Doldrums.”