Probably the foremost must-see act among South by Southwest's new buzz bands – and one that isn't playing a half-dozen shows like all the others – Broken Bells made its live debut last night at the Stubb's outdoor amphitheater in downtown Austin, part of National Public Radio's sponsored showcase. It was a pretty fascinating set, if a bit sleepy. The group is led by Shins singer James Mercer and production wiz Danger Mouse (Brian Burton), the latter of whom mostly played drums but also came out front on keyboards and a little guitar. They were backed by an impressive six-member unit, and the whole stage was awash in swirling black-and-white video graphics that sort of looked like charcoal sketches come to life.

Musically, though, the 45-minute set was like one big, colorful kaleidoscope, with lots of traces of Beatles and "Pet Sounds" psychedelia meshed with the spacey funk Burton crafts in Gnarls Barkley, all with Mercer's great pop voice laid on top. Highlights include the opener "The High Road," which also opens Broken Bell's just-issued eponymous album on Columbia Records, plus the more ambient "Trap Doors" was pretty mesmerizing. There was never a wow-inducing moment, though -- whereas the preceding set by Sharon Jones & the Dap Kings sent ecstatic chills through the crowd five or six times -- and the music often felt so slick and stylized it sort of reeked of being made specifically for car commercials. These days, though, that's still kind of cool. ALSO LAST NIGHT: 1) I caught the first five songs of Spoon's one and only SXSW set at Stubb's after Broken Bells (I didn't hang around longer because they have two shows at First Ave in two weeks). Nice to hear them sprinkle in old tunes such as "Don't Make Me a Target" and "Someone Something" alongside new ones, including the extra-feisty opener "Written in Reverse." 2) After that, I headed to see Andrew W.K., with whom I had an intense interview earlier in the night (more on that later). Coming back from a five-year hiatus from full-on rock shows, the Michigan-bred madman was as wild as ever and had the second-story floor of the buffalo-sized Buffalo Billiards shaking mightily from all the fans jumping during "Party (We Don't Stop)." 3) I ended the night on a somber but perfect note, as South St. Paul music hero Grant Hart finished his acoustic set at Lamberts with an impromptu of Alex Chilton's Box Tops classic, "The Letter." There weren't a million children there, but those who were there were indeed singing. (James Mercer photo by Tony Nelson. See more photos and reports at www.startribune.com/sxsw)