When Anthony Kiedis chose Bob Dylan as headliner of the inaugural New American Music Union, the Chili Pepper probably didn't envision the rock icon filling the better part of the set with shuffling Western swing and such non-classics as "Spirit on the Water" and "Beyond the Horizon."

Dylan topped a bill of relative youngsters Saturday night in a SouthSide Works parking lot that was magically transformed into a festive urban concert venue.

American Eagle and Live Nation deserve credit for creating a good vibe from the start. For instance, rather than gouging people for a basic like water, as most of these events do, they passed out nice water bottles to be filled by the coolers lined up near the entrance. Fans also had in-and-out privileges if they felt like taking a break or hitting a South Side bar.

As for the music, it was slightly better on paper. After a quickie by stylish British band The Duke Spirit, Canada's Black Mountain hit the stage with a set of stoner rock so heavy it made you feel stoned just listening to it. With bass lines that rumbled in your chest and the ghostly harmonies of Stephen McBean and the charmingly aloof Amber Webber, the band delivered metal with an indie-rock aesthetic and a wink and a nod to Black Sabbath and the prog jams of early Pink Floyd.

The most thrilling moments of the day came from Gnarls Barkley, making its Pittsburgh debut. The team of Danger Mouse and Cee-Lo, fronting a band that could have backed James Brown at the Apollo, offered a mix of old school soul and chaotic rock 'n' roll on songs such as "Run (I'm a Disaster)," "Just a Thought" and a cover of Violent Femmes' "Gone Daddy Gone."

Cee-Lo, a vision in white, is a sizable and dangerously good frontman who could hold his own with a soul, R&B, hip-hop or punk band -- certainly a rare combination. "Crazy," still one of the best singles of the decade, the ethereal "Neighbors" and a perfect cover of Radiohead's "Reckoner" were worth the price of admission. Gnarls could very well have been the headliner, especially with the added benefit of a more dramatic night set, and everyone would have gone away happy.

The group could definitely should have been higher on the bill than Spoon, who, with a more clinical style of indie-funk, paled by comparison. Spoon's more spare grooves never moved the masses, even with the band's bouncier material like "You Got Yr. Cherry Bomb" and a cover of the Rolling Stones "Rocks Off."

As expected, the Raconteurs came out and shredded, with the dual guitar and vocal attack of Jack White and Brendan Benson. They kicked the songs back and forth with wild abandon and sledgehammer riffs that brought to mind "Physical Graffiti." With the exception of "Steady As She Goes," the songs aren't as catchy as the White Stripes, but they make up for it with crazy and unpredictable walls of sound. "Rich Kid Blues" showed how great a singer Benson is, while the finale of "Blue Veins" was a slow burn that caught fire with White's blues licks.

Dylan could have made the evening peak with a crowd-pleasing set, but that's not really his interest. Perhaps this is just another phase, but these days he fancies himself more of an old-time troubadour with a thing for swing (he's my favorite artist of all time, but I didn't sign on for this). The focus was heavy on latter-day material that most of the fans probably didn't even know such as "The Levee's Gonna Break" and "Nettie Moore," but even such classics as "Tangled Up in Blue" and "It Ain't Me, Babe" were adapted to the loose-limbed, ballroom style.

Dylan, on keyboards that you couldn't really make out, was croaky on vocals and that once-beautiful phrasing was just ugly, but he actually outshined his band, which didn't seem its usual "crack" self. After sending a lot of people to the exits early, he did put smiles on faces with "Ballad of a Thin Man" and an encore of "Like a Rolling Stone."

It was a set that may have worked better in the daylight, sitting on a grassy hill. Coming after Gnarls and the Raconteurs, it was an anticlimax, and the key to a good festival is building excitement with each act. Flip the order to Spoon, Dylan, Raconteurs and Gnarls Barkley, and this Union would have been hot.

The other disappointment is that throughout the two-day festival, none of the artists appeared in each other's sets. It was too much to hope for that we'd see White with Dylan or Kiedis with Gnarls, but those kinds of spontaneous chemistry experiments are worth thinking about for next year.