When U2 got together, in September, 1976, Bono, Adam Clayton, and the Edge were sixteen, and Larry Mullen, Jr., was fourteen. At first, they called themselves the Larry Mullen Band, then Feedback, then the Hype. They changed the band's name to U2 the following year while playing at a community center in Howth, a gorgeous little seaside town near Dublin. When U2 released its first album, “Boy,” in 1980, half of its members were still teen-agers. Which is all to say that a lot has changed since then. The men are now in their fifties, and their band is almost forty years old. More than seven million people bought tickets to U2's last tour, which began in 2009, ended in 2011, and involved a hundred-and-sixty-foot tall stage called “The Claw.” (It remains the highest grossing tour of all time.) During those shows, a recorded message from Desmond Tutu introduced the song “One.” Last week, during one of the band's new, smaller-scale shows at Madison Square Garden, Stephen Hawking provided the intro to “City of Blinding Lights” while, on U2’s giant video screen, the Earth spun: the ultimate community center.

The band is playing the Garden eight times this month as part of its “Innocence + Experience” tour. (The last show is tonight; after that, the tour heads to Europe.) It's a grandiose, compelling, ridiculous, and moving show—a typical U2 production, in other words. The band originally planned to play pairs of themed concerts, with an “Innocence” night followed by an “Experience” night. That would have presented concertgoers with a dilemma, however, and so the two nights were combined. The result is a show that is, in broad strokes, about youth and age. Last Thursday, the “innocence” half was elegiac and angry, with Bono singing about the Troubles and the death of his mother, while the “experience” half was more expansive, optimistic, and uplifting. In this way, the narrative was essentially Christian. Experience was understood as the rediscovery of innocence.

Technology is at the center of the new show, though on a smaller scale than on the last tour. The arena is bisected, lengthwise, by a giant, two-sided video screen. There’s a catwalk inside the screen, and the members of U2 spend a fair amount of time strolling around inside their own images, floating in space above the crowd. During “Cedarwood Road,” a new song about growing up in Dublin, Bono appears to be walking through a drawing of his old neighborhood. When the Edge plays his guitar solo on “Until the End of the World,” he does it from inside the screen, while Bono’s image is hugely magnified beside him: the singer appears to be holding the guitarist in the palm of his hand. “Until the End of the World” is a Biblical song—it has Bono, as Judas, singing to the Edge, who represents Jesus by means of a righteous guitar solo—and, as the solo continues, confetti made from ripped-up books falls onto the crowd; when I reached up and grabbed a page, it was from Dante’s “Divine Comedy.” The whole sequence was inventive, absurd, and spectacular—an echo of the band’s maligned, but brilliant, PopMart tour.

Other moments were simpler and more moving. “Iris” is about Bono’s mother, Iris Hewson, who died when Bono was fourteen. During that song, an old home movie of Iris running on the beach flickered in space; as Bono sang, he reached out to her with one hand and, onscreen, they almost touched. At other times, the messianic enthusiasm of the crowd elevated the show into something like a church service. As “City of Blinding Lights” began, horizontal and vertical bars of light floating throughout the arena suddenly lit up, forming bright-white crosses and sparking visible euphoria. During “Pride (In the Name of Love),” a group of middle-aged men standing in front of me held their hands over their heads, curling their thumbs and forefingers to create little hearts. When Bono asked the crowd to “sing for the peacemakers” in Charleston, Ferguson, Palestine, and other places, they sang as loudly as they could. These sorts of feelings aren’t usually expressed at rock concerts. The goodwill lasted even through a long speech about AIDS drugs for mothers and children, during which Bono gave thanks to Nancy Pelosi.

At moments like that, it’s hard not to think about how ironic (or perhaps “ironic”) U2 used to be. Seventeen years ago, the band members were arriving onstage in a giant lemon, revelling in bad taste—pioneering, perhaps, the resplendent, knowing, awkward, and clever awfulness we can find, today, in Kanye West’s “Bound 2” video. Back then, they mocked and resisted the pop-culture machine, which co-opts even the subtlest ideas by turning them into brands, slogans, and images. They knew they were part of that machine; in a sense, they recognized their own ugliness. Now, especially in its live show, U2 seems to shy away from everything ambiguous, ugly, and false—a problem for a band that wants to sing about love, beauty, and the state of the world. The band's relentless positivity is another kind of falsehood.

In the early nineties, U2 mounted a more cerebral and adventurous tour called “ZooTV.” That tour’s guiding metaphor was television; Bono used a remote control to channel-surf on the show’s giant screens. He flipped between local stations, the Home Shopping Network, the nightly news, and scenes from the concert in which he was currently performing; sometimes, he landed on more unsettling material. Late in the tour, the band began staging live video links with people living in Sarajevo. At one concert, at Wembley Stadium, Bono spoke from the stage with three women living there. “Do you really know what’s happening here?” one of the women said. “I think you don’t know, because you don’t do anything for us.” Bono, speaking before a silent crowd, said, “We feel rather ridiculous tonight, being in a rock and roll band, in this fantasy of ZooTV, with your reality there in Sarajevo.” Then the concert switched channels, as it were, and U2 played another song. This felt “uncomfortable,” Bono told the crowd, although, in a sense, it was “no more obscene than channel-hopping at home or in a hotel room.” (During the same show, Bono—dressed, appropriately, as the devil—called Salman Rushdie, who was then in hiding, on the phone; in a surprise twist, Rushdie turned out to be at the concert and came onstage.)

During those concerts, U2 acknowledged that its own peculiar combination of spiritual populism, rock theatricality, and social seriousness could be bizarre, unsettling, and even offensive. That didn’t make it worthless; in some ways, it was more effective for being strange. U2 turned that strangeness into art. The band's great subject became the separation of meaning from meaninglessness. Presumably, there’s still a vault at U2 H.Q. where all of these ideas are stored away; unfortunately, the band seems to have gotten bored with them around the year 2000, when its comeback album, “All That You Can’t Leave Behind,” re-conquered radio with “Beautiful Day.” The central irony of U2’s career might be that, having become sophisticated critics of media sophistry, the band simplified its outlook just before 9/11. It could’ve been the perfect band during the Bush years. Instead, U2 became normcore. Its most recent albums have been welcoming and unselfconscious; when performing, the band acts as though its mixture of emotional appeal, pop kitsch, and political sloganeering is utterly unremarkable. Aesthetically, U2 has become what it once critiqued.

There are any number of explanations for why U2 changed. The interests of its members may have shifted. Perhaps they grew tired of being “cool” and “postmodern.” It’s said they got scared when “Pop” didn’t sell. Perhaps Bono’s humanitarian work made him less inclined to mock himself and others. Also, the media landscape which felt so problematic in 1991—frivolous-yet-momentous, trivial-yet-urgent—is now a mainstream, daily experience; we encounter it whenever we click around the Internet. Perhaps it no longer seems worth protesting. One has to keep things in perspective, too. The songs still sound great; you can’t argue with the Edge’s guitar tone.

Even so, it’s hard not to miss the U2 of the nineties. The band was a pop phenomenon that acknowledged the limits of populism; it explored the overlap of anxiety and piety; it was in touch with the times; it knew that sincere statements always evoke their opposites, and must struggle to survive them. For that version of U2, the combination of innocence and experience wasn’t more innocence, but irony—a useful attitude in a world overflowing with pop culture, pop politics, and pop spirituality.