For us Fall Out Boy freaks, the past decade has been a disorienting whirlwind. What once began as a pop-smart, heart-on-sleeve emo outfit has gradually swelled -- album by album -- into an overblown arena-pop caricature. But even if diehard fans have found this transition perplexing, FOB have worked wonders with their ironic musical absurdity.

The quartet's five-year hiatus has only magnified their tongue-in-cheek expansiveness. 'The Phoenix' opens their long-awaited fifth album with a potpourri of musical stupidity: a pulsing electronic throb; Patrick Stump's hyperactive, soulful melisma; comically grandiose orchestrations ripped from a Hans Zimmer score. In the past (on albums like 2007's 'Infinity on High'), the band never sacrificed their pop smarts and instrumental power for the sake of cheap sonic thrills; 'The Phoenix' marks a tragic tipping point: gimmicks for gimmicks' sake.

Elsewhere on 'Save Rock and Roll,' Fall Out Boy continue to expand their ambitions, tackling (or maybe even spoofing) the entire Top 40. Fortunately, most of their experiments are jaw-dropping for the right reasons. 'My Songs Know What You Did in the Dark' is a more nuanced version of 'The Phoenix''s overwrought bloat. Here, the skittering programmed snares, timpani-styled tom-tom rolls, backing-vocal shrieks and police-siren guitar riffage build with a sense of urgency and purpose.

There's a New Wave sheen to the wide-screen synths of 'Alone Together' and the soulful rhythmic thrust of 'Where Did the Party Go'; 'The Mighty Fall' sports a loopy hip-hop attack (despite its misplaced Big Sean cameo), landing somewhere between Jay-Z and mid-'00s Beck. But the most surprising track here is the most subdued: the earnest, Americana-styled 'Young Volcanoes.'

As expected, the "try anything once" aesthetic wears thin at times. The closing title-track is a piano-ballad-turned-arena-rock car-crash, featuring goopy strings and the awkward croon of Sir Elton Freaking John. Elsewhere, Courtney Love's shoehorned, tuneless banter on the dance-punk assault of 'Rat a Tat' is the low point in the band's entire catalog.

But there are five glorious touchdowns for every jarring fumble. Ultimately, the world needs bands like FOB -- bands with a sense of the grandiose and absurd, bands unafraid to "save rock and roll," or fall flat on their faces trying.