It was well into the concert's second half when a happily drunk fan shouted, "How sweet is the world?"

But he represented the sentiment of the entire crowd Friday night as the Dave Matthews Band hit the stage at the Post-Gazette Pavilion. Though he may have been mixing his words (he yelled during the opening chords of the DMB's "One Sweet World") he was exactly right -- from the limbs dancing and flailing throughout the audience to the grooving, happy and ubiquitous vibes, the show was predictably fun and laid back, but a spectacle nonetheless.

Opening trio State Radio set the stage with its brand of rootsy funk-folk to a sadly desolate venue.

The band finished its solid performance as most were moseying in at one of the Pavilion's many vending areas.

After a quick set change, and with both the seated section and the open lawn filling to near capacity, the house lights dropped. But with the sun still in the sky, the dramatic move didn't have quite the effect the band may have hoped.

As sound began to flow through the speakers, it seemed like Pink Floyd might actually be bounding on stage; three giant, glowing video screens blocked the view of the stage ("The Wall" for the 21st century, perhaps?), supplanted by spacey white noise with increasing intensity.

Meant to introduce a band best known for summery jam-rock, not avant-garde space music, the show began on an off-putting foot.

Mr. Matthews and company, including violinist Boyd Tinsley, bassist Stefan Lessard, saxophonist LeRoi Moore and percussionist Carter Beauford, as well as tour regular and talented guitarist Tim Reynolds, recovered quickly. With the sudden pounding of Beauford's drum kit, the screens became clear and revealed a band ready to get down for more than two hours. And get down it did; some of the biggest audience reactions came from Matthew's gummy-legged dancing, Tinsley's energetic, violin-in-hand moves and close-up screen shots of Beauford's constantly smiling face, his body in Steelers garb.

The DMB opened with the dark and driving "Don't Drink the Water" from 1998's "Before These Crowded Streets," one of only two tracks from the band's most underrated album (the other being the band's strongest groove of the night, the irresistibly danceable "Rapunzel").

From there Matthews led the crew through familiar territory: the joyous "Everyday" had the audience so elated I'm surprised more didn't spontaneously hug; "Crash," while likely the band's most played song, was a believably emotional performance; the bluesy "Smooth Rider" found Matthews pumping up his vocal intensity to 11.

The DMB also played some lesser-worn tunes, including the breezy, perfect summer kickoff "So Damn Lucky" from Matthews 2003 solo album, "Cornbread," a funky, whirling, bluegrass-leaning tune and "#27," a slower, meditative jam with an interwoven saxophone line that placed the performance in a smoky club.

The band closed out with a rousing rendition of Sly and the Family Stone's "Thank You (Falettinme Be Mice Elf Agin)," which proved a great encore choice -- the crowd kept singing the chorus long after the musicians had left the stage.

One thing was clear -- the guys know how to play. The band's been at this for a decade and a half now, perfecting the art of the arena show for at least two thirds of that, and it shows.

But the key word here is arena show, where the entire production is flawless, not just the music.

Solos, while played impeccably, and most often by Reynolds and Moore, lacked the spark of true improvisation, while the musical grooves, unlike the late Phish, for example, unfolded cleanly and in perfect procession. Ultimately, the discerning listener's got to ask: though jam bands thrive on onstage creativity and improvisation, how much can an act really flex its musical chops when everyone from the lighting guy to the beer vendor can guess where each song is going next?

So while the band continues to truck on as one of the biggest summer tour juggernauts around and put on a show that is nothing short of inspired and inspiring -- ask any from the crowd who remained dancing for two hours plus -- there's an element of surprise that's lacking from the former kings of the jam. And if they could reclaim that missing piece, the audience would be so damn luckier.