With a title cribbed from a Van Gogh letter and a song produced by Babyface, Infinity on High suggests that Fall Out Boy are starting to take themselves seriously. They're not. Smartass lyrics and all-ages rock club riots are still the order of the day. Nothing here dethrones their pop-punk creative zenith, the 2005 smash "Sugar, We're Going Down," but "This Ain't a Scene, It's an Arms Race" -- with its clomping beat and call-and-response breakdown ("Sing until your lungs give out!") -- is a blast. The Boys could have managed a risk or two here, but play it safe instead.