'From Under the Cork Tree' is one of the most ubiquitous albums in iTunes libraries these days, and it's easy to see why. Fall Out Boy's third effort is full of 11 energetic pop-punk songs and a couple slower pieces for variety. Fun as it may have been, the three-chord catchy melodies and the creative limitations of the genre leave listeners wondering what else this band can do.

Enter 'Infinity on High.' The album begins not with a catchy Patrick Stump attack but with a dedication by Jay-Z. Ten seconds into the album and it's already clear there is going to be a significant stylistic distinction from the band's previous work. Regardless of how well the songwriting will keep up with the sound diversification, this is a very good thing ' it's undeniably refreshing to listen to a Fall Out Boy CD and be able to tell when the song changes.

A harder-working group than many give them credit for, the band's 2007 offering comes with plenty of twists on the typical pop-punk formula. It seems like each song contains something just a little bit goofy or off-beat, like surprising instrumentation or retro-style harmonies. It's refreshing to hear Fall Out Boy take themselves less seriously, and it's great to hear no lapse in Pete Wentz's excellent songwriting, too.

'This Ain't a Scene, It's an Arms Race' is the lead single from the album, and has hit the charts harder than any of the band's previous offerings. Wentz hails it as a hip-hop song written for punk, and these two disparate styles come together surprisingly well with Stump's trademark strains and the titular line that almost demands fist pumps.

Also noteworthy is 'Hum Hallelujah,' featuring a chorus singing Leonard Cohen's classic while the trademark palm-muted power chords drive along behind. The band steps further into the realm of pop with the oh-so-cleverly titled 'I'm Like A Lawyer With The Way I'm Always Trying To Get You Off (Me + You),' but its saccharine-sweet line 'if I woke up next to you' sounds like it was ripped directly out of a 90s boy band love song.

Lyrically, little has changed. These tracks are still laden with the typical too-cool analogies and incisive neologisms that filled the band's previous works. 'Penny for your thoughts, but a dollar for your insights,' and 'bandwagon's full, please catch another' are just a few of the clever one-liners riddling this album. Catchy as they may be, Fall Out Boy seems to dance around the point with their trendy metaphors while leaving the listener wondering what they're actually talking about. 'I love you like there's a chapel in a hospital'? I'm stumped.

'Infinity on High' is the sound of the band stretching its creative boundaries and largely succeeding. Fans will appreciate the trademark pop-punk that still abounds, and fence-sitters will enjoy where the band took its sound. Let's be honest: You can't really hate Fall Out Boy unless you're really trying to, and this album will make it even harder.