Since "Young Folks" was such an inescapable smash for them in 2007, it would have been easy for Peter Bjorn and John to try to follow in its bubblegummy footsteps and become a happy little band with a strong line in novelty songs.

Instead, the trio first released an instrumental album (Seaside Rock) in late 2008 and then returned with the much darker, less bubbly album Living Thing in the spring of 2009.

That being said, Writer's Block wasn't that upbeat, and apart from "Young Folks" and a couple other tracks, its sound and lyrical themes were pretty gloomy at heart.

There were plenty of guitars, though, and that's a big difference, as Living Thing continues the trio's effort to refine and reduce its sound into just the essential elements needed to put the songs across.

To that end, guitars make only occasional cameos and basses, too, are rarely heard, as the bulk of the album is based around percussion and voices.

The percussion isn't straight drums, usually they are tweaked or electronic, and often the instruments the band does feature, like piano and synthesizer, are used for their percussive value.

It's an approach often found in hip-hop, and it's possible that the bands' association with Kanye West opened their ears to new ways of presenting their songs.

Like Kanye on 808s & Heartbreak, PB&J are also infatuated by the icy textures of synth pop on Living Thing.

There are healthy amounts of cold synths, FXed guitars, and detached vocals, but like on 808s, there is a very human heart beating beneath the machines and through all the songs.

You can hear it in Peter's vocals, in the heart-rending lyrics, in the heartbreak beats, and in the emotionally electric songs.

The only song with any hope of replicating a fraction of "Young Folks"' success could be the first single, "Nothing to Worry About," which instead of whistling has children's voices in the naggingly catchy chorus as the hook.

There are plenty of songs that do deliver the expected pop hooks and emotional weight, though.

"Living Thing," with its singalong chorus that references the ELO song of the same name, the '50s pop-influenced ballad "Stay This Way" (which has a ripping stylophone solo), the comforting and sweet "Just the Past," and the New Order-ish "It Don't Move Me" are as good as anything the band has ever done.

It's been kind of a long journey from the simple power pop of the band's first records to the complex and highly arranged sound of Living Thing, but there are no signs that the trip is over.

And if Peter Bjorn and John keep putting out albums as challenging, intelligent, and emotional as this, there is no reason for anyone to get off the bandwagon any time soon.