It's been quite a year for the whistling Swedish trio Peter Bjorn & John. After the breakout success of the inescapable and ridiculously catchy single "Young Folks," PB&J has garnered praise far and wide from seemingly everyone including the likes of Kanye West, who sampled the song on a mixtape and even asked the band to back him onstage at a show in Sweden. The boys also racked up an MTV Video Music Awards nomination for best new artist and are currently headlining gigs across the U.S. in support of 2006's "Writer's Block."

At PB&J's stop at New York's Roseland Ballroom on Sept. 7, the group delivered a lively and energetic set in light of the fact that the half-attentive crowd spent most of the night wandering around the spacious venue rather than watching the activity onstage.

After teasing the audience with the intro of "Young Folks," PB&J kicked things off with the steel drum-backed hand-clapper "Let's Call It Off," which found group member Peter Moren bouncing around playfully, which he continued to do throughout the night. The brief set was dedicated primarily to "Writer's Block," and the band hit all the album's high notes, such as the distortion-washed, shoegaze-y "Start To Melt," the anxious and eerie "Chills" and "Paris 2004," with its irresistibly charming chorus.

The dark and spacey "Amsterdam" sounded especially hypnotic live and managed to perk up the audience's attention, as did, expectedly, "Young Folks," which featured guest vocalist Nicole Atkins filling in for the Concretes' Victoria Bergsman, who appears on the album version. The main set closed with a guitar-heavy cover of the Concretes' "Teen Love" and the militaristic ""Objects of My Affection" before the group returned for a one-song encore, "Up Against the Wall." The extended, feedback-drenched and bongo-backed breakdown at the song's end brought Moren out into the crowd for one final hurrah.

British pop outfit the Clientele opened the evening with an abnormally short and swift set. The band rolled through several songs off its latest Merge release, "God Save the Clientele," including the light and summery "Here Comes the Phantom" and the disco-tinged "Bookshop Casanova." Throughout the set there appeared to be some sort of awkward band member and/or band/audience tension festering, though it wasn't exactly clear what was going on. In any case, the Clientele concluded its set with the speedy instrumental number "The Dance of the Hours" before quickly exiting the stage.