The band dealt out intensity to a sold-out Sin City crowd

For a few moments at Las Vegas’ Sam Boyd Stadium, the medium was truly the message. For their first PopMart show, U2 took the stage dressed suitably camp — the Edge in cowboy hat and Fu Manchu mustache, Adam Clayton in surgical garb, Bono in hip-hop-style hooded sweatshirt, jabbing the air like a boxer. The PA blasted M’s ”Pop Muzik,” and the McDonald’s-style arch lit up a garish yellow. Finally, all of U2’s hype about ”techno” and kitsch sprang vividly to life.

Of course, nothing is ever simple with U2, and so it went with PopMart. The show attempts, wisely, to tone down the overkill of 1992-93’s Zoo TV tour. Drive-in-like screens broadcast Pop-art cartoons (e.g., the evolution from ape to man to shopping cart). But despite the Green-Giant-size olive and lemon, this stage was as pared down as the band itself. With a close-cropped Bono out front, U2 bore down intently, as if worried about playing out of sync (indeed, after one verse of ”Staring at the Sun,” the band stopped and began again, in a different tempo). Apart from the Edge’s sing-along of ”Daydream Believer” — with the lyrics displayed on screen, turning the 38,000-seat stadium into the world’s largest karaoke bar — the presentation was mostly stern. Looking like a Celtic Popeye, Bono stalked the stage, sans his once stallionlike aplomb.

For any other band, a low-key ambience wouldn’t be a problem. For U2, it opened the floodgates to a number of them. The set moved between Pop songs and a smattering of anthems. Digging their boots into dark Pop material like ”Last Night on Earth” and ”Please,” U2 proved they aren’t a nostalgia act — youthful rabble-rousers frozen in time. But with Bono holding his mighty roar in check, ”I Will Follow” and ”Pride (In the Name of Love)” were shockingly perfunctory — modemed in. U2 once magically transformed football fields into intimate halls. But PopMart was oddly repressed, as if the band feels trash-kitsch culture precludes passion.

Forgiving U2 any first-night glitches, the concert was a microcosm of the conceptual overthink that currently surrounds them. The band hyped Pop as a leap into electronica, which it isn’t; they also claimed to be tweaking pop culture, then participated in a TV ad campaign that placed them, with no irony, alongside Tim Allen. By pretending to hop aboard the ’90s sarcasm train when it really doesn’t, PopMart only makes the band look cynical.

And about that huge lemon at stage left: It may be a cheeky homage, but you couldn’t squeeze an ounce of humor from the solemn way it was used. It was yet another maddeningly mixed message from a band caught up in far too many of them.