U2 has always been known for the grand gesture, most often thanks to its front man's gift of gab. Yet the start of the Irish quartet's show at Philadelphia's Wachovia Center tingled the spine before Bono uttered a word.

The Edge's guitar shimmered like light made audible as curtains of reflectors draped the stage and huge hanging lamps burned red. While his band mates played the intro for "City of Blinding Lights," Bono appeared at the crown of the elliptical catwalk 30 or so rows into the crowd; he used the moment to just eye the ecstatic faces as the sound pealed all around and a burst of glittering confetti greeted him from above.

Amplifying the electric atmosphere, U2 turned the spotlight on its fans for the song's chorus. High beams from the stage illuminated the audience as Bono sang -- and the crowd shouted back at him -- "Oh, you look so beautiful tonight." It made for a warm, wonderful greeting and set the stage for more than two hours of uncommon communion between the world's biggest rock band and some 20,000 of its devotees.

More than any major group of the past 20 years, U2 dissolves divisions between the strata of pop-music enthusiasts. Preteens and graying baby-boomers, alt-rock diehards and young metal-heads -- they all bonded in Phillie over this rarest of creatures, a rock band that gets more credible as it gets older. The foursome has managed to expand its audience even as it continues to evolve artistically.

U2's Vertigo Tour has played to sold-out arenas and largely glowing reviews across North America since late March. As with the last tour's return to essentials after the band's over-the-top extravaganzas of the late '90s, this 20-songs-plus show stresses sound over spectacle. The set list ranges from highlights of 2004's How to Dismantle an Atomic Bomb album back to tracks from the band's 1980 debut (Boy) that haven't been heard live for many years.

The most striking aspect of the Philadelphia show was its sheer emotional heft. That the band -- gray-haired bassist Adam Clayton and ever-boyish drummer Larry Mullens Jr. joining Bono and the Edge, all in their mid-40s -- can keep this hearts-and-minds intensity up night after night is a marvel. The set plays out in a thematic arc, moving from a burst of bright, energizing numbers to sequences that emphasize the personal, the political and the social in turn.

No recent U2 song reaffirms the band's rock'n'roll roots like last year's single "Vertigo," all roughneck riffs and headlong rhythms. "Elevation," so flat on 2000's All That You Can't Leave Behind, appeared in a grittier, superior guise. Other shows on the tour have featured early songs "Gloria" and "Party Girl," but this night's most welcome rarity was "Electric Co." Bono managed to mix in lines from "Send in the Clowns" and the Who's "I Can See for Miles," while Edge added a twisted-metal guitar solo.

The heart of the show came with the soaring "Miracle Drug" and quietly devastating "Sometimes You Can't Make It on Your Own," two of the richest U2 songs in years and the most moving from Atomic Bomb. Bono's rapport with large crowds is axiomatic; that he can sing "Sometimes" -- a heartbroken aria for his late father -- with both outer engagement and inner resource goes beyond that.

Moving from the personal to the political, Bono donned a bandana scrawled with a Christian cross, Star of David and Islamic crescent for the 21st-century blues stomp "Love and Peace or Else." A famous admirer of this country, Bono extolled the promise of America in his between-song semi-sermons even as he hinted at the dangers of the nation not living up to its historical example.

During "Bullet the Blue Sky" -- the band's classic, poetic indictment of the military-industrial complex -- a blue fighter plane was projected onto the red curtains of reflective beads as the Edge's Hendrixian white noise provided the score. Bono interpolated the refrain of "Johnny Comes Marching Home" into the song, acting out the drama by pulling his bandana down like blindfold.

Careful not to blame the messengers of the Iraq war, Bono dedicated a hymn-like version of "Running to Stand Still" to "the men and women of the U.S. military -- may they come home safely." The United Nations charter for human rights then scrolled across the above-stage screen, surely meant as a double-edged reminder of what's at stake in any conflict. The political met the spiritual with the Martin Luther King elegy "Pride (In the Name of Love)" and a magical version of the chiming, one-world mantra "Where the Streets Have No Name."

In preacher mode, Bono noted that "the American dream isn't just an American dream but an Asian dream, an African dream." He recalled that, as a boy, his first impression of America was seeing Neil Armstrong walk on the moon; crediting John F. Kennedy's direction, the singer implored George W. Bush (and Tony Blair) for similar leadership to end global poverty, "not to put a man on the moon but to put mankind back on earth."

Even if "One" began as a touching plea for marital harmony, the ballad has morphed into an entreaty for universal concord. Bono asked the audience to pull out its cell phones, and the stage lights dimmed; as the band played in the dark, the little blue lamps lit up the crowd like candles. What would've been hokum from any other act was arena theater from U2.

The initial encores touched on the Euro-adventurism of 1991's Achtung Baby and the ironic social commentary of subsequent tours. The Edge's industrial din drove an exciting revision of "Zoo Station" and a glam take on "The Fly." Screen titles encouraged the crowd to "shut them out" -- "them" being junk media, empty advertising and crass politicking -- and "you will win." (Ads for U2 Ipods probably don't count.) "Mysterious Ways" was as close as U2 gets to simply dancing and romancing; even the normally stoic Clayton grinned helplessly on the catwalk as he watched the crowd sway to his sinewy bass line.

By the end of "All Because of You," Bono's vocal cords were frayed, and he leaned on the Edge's harmonies -- the group's secret weapon -- and the chanting crowd for the vintage finale of "40." The show ended as it began, invoking the bond between band and audience.