BY ZACHARY HERRMANN

For all the stateside respect and popularity earned in the last three years, Peter Bjorn and John still had a lot to prove Saturday to 9:30 Club's sold out crowd - mainly, that the band hasn't forgotten how to have fun.

The Swedish pop trio's latest album, Living Thing, took an unexpected turn into dark minimalism, drum loops and synthesizers. And while it's great to see PB and J so willing to shake things up, the self-serious new wave thing leaves you feeling like you're trapped in a Bret Easton Ellis novel. The cold detachment is very much imbedded in the album's premise. After the engrossing hooks of Writer's Block and Falling Out, though, that's not much of a consolation.

How, exactly, the new LP will go down in the longer scheme of PB and J's career remains to be seen - tangent or turning point? - but regardless of where the band goes from here, Saturday's live set in Washington reaffirmed its ability to elevate album material through knockout performances. Splitting evenly between tracks off of Living Thing and Writer's Block, PB and J reaffirmed its status as one of the most pleasantly surprising live acts around.

While Björn Yttling and John Eriksson are talented in their own respects, Peter Morén is largely responsible for the dynamism that drove nearly every song into a fiery crescendo. Seems no one has told Morén indie pop guitarists aren't supposed to solo anymore.

Too often, groups capable of crafting textured, compelling studio efforts (Vampire Weekend, the Shins, the Hold Steady to name a few) fail to do much in translating good album material to the stage. You get the feeling that catching these bands on any night is basically the same as any other night - same notes and, more or less, same songs.

PB and J are not of this ilk - to put it bluntly, the band rocks the fuck out. Beginning with "Start to Melt" (opener "Just the Past," one of Living Thing's better offerings, fell a little flat), Morén unleashed murder on his Gibson SG. Dressed in a dapper white blazer and neck-kerchief/ tie hybrid, the guitarist flew all over, frequently up on to the PA system, making like an animated Swedish guitar god.

The extended jams, rather than coming off as tacked-on, spruced up a few of the blander new numbers. "I'm Losing My Mind" still sounded impossibly insincere (especially given the Euro-chic outfits on the stage, c'mon, none of these guys appear to losing their minds) until Morén's frenetic playing cut through Björn's droning vocals. Unfortunately, much of the new material required open spaces between bass and synth loops - basically, whenever Morén's guitar wasn't tearing through the speakers, PB and J's new moody ambience was replaced with copious amounts of bar chatter.

Fan favorites like "Young Folks" (sorry kids, there was no whistling this time!), "Amsterdam" and the Kanye West-endorsed "Nothing to Worry About" all kept the crowd dancing and relatively less chatty. Plenty of people sang along as Morén spit out bits and pieces of recognizable songs in a medley of various teases (most prominently, the refrain from Joy Division's "Transmission") during the sprawling show-closer, "Up Against the Wall."

On album, PB and J's transparent influences of late may be a bit troublesome. The band's previous albums developed a very distinct sound that wasn't mired in overt sonic references, which is something Living Thing definitely does not have going for it. However, the inspiring nods have been no detriment to the live show. A spitfire rendition of The Feelies' "Fa Cé-La" sat comfortably up against "Lay it Down," during which the band handed out cardboard mask visages of each of the three members.

The entire crew came out - one man introduced to us as "Ross" played bongos - and danced in front of the tongue-in-cheek minimalist background: white type on a black sheet, with only "Peter Bjorn and John" and "backdrop" repeated again and again underneath.

Even if the tough-talking put down song, with the refrain "Hey shut the fuck up boy/ You are starting to piss me off," wasn't one of PB and J's best, the band sure made the best of it. As into it as the crowd was, the real party looked like it going on up on the stage.

Set list:

1)      Just the Past

2)      Start to Melt

3)      It Beats Me Every Time

4)      Amsterdam

5)      The Chills

6)      It Don't Move Me

7)      Nothing to Worry About

8)      Living Thing

9)      Young Folks

10)  I'm Losing My Mind

11)  Let's Call it Off

12)  Objects of My Affection

13)  Lay it Down

14)  Fa Cé-La [The Feelies]

15)  Stay This Way

16)  Up Against the Wall (with medley)