The Who kicked off the U.S. leg of their first world tour for more than 20 years on Tuesday with a two-hour set that included a full complement of classic hits, a smattering of new material, and some rough edges.

The legendary British rock band which came to prominence in the early 1960s with songs about youthful rebellion and alienation has only two of its original members - singer Roger Daltrey and guitarist and songwriter Pete Townshend.

Two other members of the original band - drummer Keith Moon and bassist John Entwistle - died in drug-related incidents.

The gray-bearded Townshend, 61, periodically pumped up the capacity crowd at South Philadelphia's Wachovia Center with his classic arm-twirling power-chord style while Daltrey, 62, looking younger in jeans and a plain blue T-shirt, belted out the lyrics of The Who's extensive back catalog.

The band, also consisting of Townshend's brother Simon on guitar, Ringo Starr's son Zak Starkey on drums, Pino Palladino on bass and John Bundrick on keyboards - fluently delivered many crowd-pleasing anthems including "Won't Get Fooled Again," "My Generation," "Teenage Wasteland" and "Behind Blue Eyes."

But they were less confident playing material from the forthcoming "Endless Wire" album, their first since 1982. They were clearly unhappy with a seven-song "mini-opera" from the album, and apologized several times for what they saw as less-than-perfect renditions of that and other new songs.

"Thank you for putting up with it. I know it's tough to hear new music," Townshend told the crowd.

The new material, such as the Dylanesque "Man in a Purple Dress" suggested a departure from the classic Who style and the concert featured two duets with just Townshend and Daltrey, providing a contrast to the high-volume rock that some critics see as a precursor to the punk rock of the late 1970s.

Despite forays into the 21st century, The Who seemed firmly rooted in the 1960s, an impression strengthened by nostalgic black-and-white videos of 1960s memorabilia and rock icons including Jimi Hendrix and Elvis Presley.

The band's focus on their classic songs seemed to please the crowd, some of whom came to relive their college days. Bob Paul, 51, a lawyer, said he had first seen The Who in 1973 when he was a freshman in college, and stayed up all night to get tickets.

Steve Toole, a 37-year-old marketing executive who had driven from Washington, D.C., for the evening, said his mother had listened to The Who's rock opera "Tommy" when he was in utero in 1969. He had brought her, now aged 70, to hear her first-ever rock concert.

"Their music just speaks to me," he said. "It's music about 'Who am I?', and I was asking myself the same question," he said.

Event/location: Wachovia Center, Philadelphia
Attendance: 16,000 (estimated)

More a Philly cheese steak crowd than a sushi set. The sold-out, cross-generational audience for this opening night of the American segment of The Who's world tour encompassed fans in their teens and 20s all the way up to the older range of baby boomers.

The crowd: More a Philly cheese steak crowd than a sushi set. The sold-out, cross-generational audience for this opening night of the American segment of The Who's world tour encompassed fans in their teens and 20s all the way up to the older range of baby boomers. T-shirts and jeans were the dominant fashion motif.

The set: A basic rock 'n' roll setup for Pete Townshend, Roger Daltrey and their supporting bandmates was augmented by five rectangular screens above the band and a longer horizontal screen above that. For opening number I Can't Explain, the five screens depicted classic images of the band in the '60s and '70s in black and white and color, while the larger screen above showed the new version of the band playing. Later on, the screens were deployed to show various psychedelic images and computerized patterns, or to display various iconic shots (Elvis Presley on Real Good Looking Boy, a salute to Britain's mid-'60s mod movement on Anyway Anyhow Anywhere).

The classics: Plenty of those were offered: Two of the first three songs were their first and second singles, from back in 1965 —I Can't Explain and its follow-up, Anyway Anyhow Anywhere. They also played 1970's The Seeker; Baba O'Riley and Behind Blue Eyes, from 1971's Who's Next, the latter track featuring singer Daltrey on guitar; and latter-day hits You Better You Bet (complete with false start) and CSI theme Who Are You.

The new stuff:Real Good Looking Boy, a Presley tribute that came out in 2004, led into a series of short songs from the British mini-opera Wire and Glass (all of which will appear on the forthcoming Who album The Endless Wire, out Oct. 24). They were generally catchy, muscular, driving Who-style rock, very much in the band's tradition.

The merch: T-shirts ranged from $35-$80, and there was a $90 button-down black shirt emblazoned with the venerable slogan "The Who: Maximum R&B." Most expensive item: a $250 black leather jacket with The Who's red-and-white Union Jack logo, plus "The Who" on a sleeve. Otherwise, there were tour programs for $20, mugs for $20, belt buckles for $15, coasters for $20, lighters for $10 and pins for $10. And, more originally, Who drumsticks for $25.

Tuesday night's Wachovia Center Concert was billed as the kickoff of The Who's 2006 North American tour. A better description would probably be "dress rehearsal."

This should not be taken as a slap at the classic rock titans led by guitarist-composer Peter Townshend and vocalist Roger Daltrey. Judging by some mid-show remarks, Townshend would be the first to say, "Amen."

"The old stuff can sound just as crappy and unrehearsed as the new stuff," Townshend told the sold-out crowd following a mid-show rendition of "You Better You Bet" which, to that point, was actually one of the better efforts of the evening.

Indeed, the concert's first half had all the earmarks of an opening-night gig.

The standard material, including the band's traditional show-opener, "I Can't Explain," "The Seeker" and a surprisingly early-in-the-set "Baba O'Reilly," seemed tentative and even, at times, a bit soft around the edges. That was also the case for the presentation's first new song, "Good Looking Boy," a paean to Elvis Presley.

And then there was the program's most interesting sequence, the 10-minute, seven-segment "mini-opera," "Wire and Glass," the centerpiece of Endless Wire, the band's first album of new songs in more than 20 years that will be released Oct. 30.

According to Townshend, it's a semi-fictional work about a rock band of a generation subsequent to The Who's that takes its individual personalities from from Townshend, Daltrey and the unit's two deceased charter members, drummer Keith Moon and bassist John Entwistle.

Townshend covered himself and his teammates by asking the audience for its forbearance before playing the piece. It was a brilliant strategy, earning instant sympathy: The work was dodgy as all get out; making matters worse, at one point, Daltrey's ear-bud monitors apparently conked out, leaving him to struggle mightily (and unsuccessfully), with the melodies.

But glimmers of the diamonds buried within poked through the rough, in particular during the catchy and ebullient "It's A Hit," and "Dream Come True," which references the death of 11 fans in a stampede before the band's concert in Cincinnati in December, 1979.

And it's a mortal lock the group will absolutely nail the entire suite when it returns in late November for its sold-out performances at Borgata Hotel Casino & Spa and the Wachovia Center.

Townshend's self-directed sarcasm had an interesting effect. What had been a program of somewhat mushy and out-of-step pieces suddenly got on track.

"You Better You Bet" was followed with the musically tricky "Who Are You," which snapped, crackled and popped it way toward being, arguably, the finest live version of the song Philadelphia has ever witnessed.

And from there on out, the set steamrolled its way toward a typically chill-producing pre-encore finale of "Won't Get Fooled Again." Along the way were stops at "Fragments," a new composition which Townshend said was composed by (not on) a computer, and a really cool "My Generation."

Individually, the players delivered.

Townshend remains a perpetual motion machine, skittering about his side of the stage, regularly serving up the "windmill" style of strumming that is as iconic as rock music gets. And his lead playing was inelegant and blunt, but oddly stylish and always to-the-point.

Daltrey is no longer the klaxon-toned belter of yore. But like Frank Sinatra before him, he's wisely chosen not to challenge the come-due toll demanded by the passage of time, but instead to adapt, transforming his tone from flashy, defiant brass to mellow, burnished woodwind.

And rest assured he's still able to summon ample amounts of spit and vinegar when necessary.

And of course, an incalculable contribution was made by drummer Zak Starkey, Ringo Starr's son, who amazed once again with his sure-handed (and footed) evocation of Moon's inimitable bashing style.

8:33 p.m. Tuesday, Wachovia Center, Philadelphia: The Who open their North American tour -- the first in four years and the first complete one led by Roger Daltrey and Pete Townshend -- with a meaty, beaty and bouncy version of "Can't Explain," under a video of their 1960s and '70s hijinks as a quartet. The Mod anthem of defiant confusion launches a two-hour show that's glorious, dubious and curious, with all the highs and lows of rock opera.

8:44: "Baba O'Riley" crests on Townshend's knifing, pummeling power chords and Daltrey's funneled, foaming, furious vocals. At 62 he can still smash and cut glass with a scream.

8:55: Daltrey shows his raw, touchingly vulnerable side on "Real Good Looking Boy," Townshend's ruminative ode to Elvis Presley, one of his and Daltrey's heroes.

9:00: Townshend explains that he wrote "Real Good Looking Boy" years ago to jump-start a Who reunion with Daltrey and John Entwistle, the band's bassist who died in 2002. Ultimately, though, the project, which Tuesday night included a Townshend elegy to Entwistle, "ran out of steam."

9:03: "Wire & Glass," the mini-rock opera that convinced the frequently bickering Townshend and Daltrey to tour again, is a 15-minute spin through Townshend's typical obsessions: the heaven and hell of fame, the saving grace of music, the circuitous search for meaning. The centerpiece of The Who's new CD "Endless Wire," due in stores next month, it's a cracked mosaic of fragmented riffs and lyrical trifles. By comparison, "A Quick One While He's Away," the Who's nine-minute, witty, wacky medley from 1966, is downright unified.

9:20: "Relay," from Townshend's aborted "Lifehouse" project, features cutting, thrashing drumming from Zak Starkey, who was tutored by none other than Keith Moon, the Who's late, lamented maniacal genius. Steadier than Moon and flashier than Kenny Jones, The Who's second drummer, Ringo Starr's son plays detonating, levitating fills on everything from "Who Are You" to "Substitute."

9:40: Daltrey and Townshend duet on another track from "Endless Wire," "Man in a Purple Dress," a savage attack on hypocritical priests ("You're invisible to me/Like vapor on the sea"). Daltrey's rugged righteous wrath proves once again why he's Townshend's best interpreter.

10:01: "Won't Get Fooled Again," The Who's most operatic, foolproof tune, is a massive dose of ecstasy, a tribal orgy. It's thrilling to watch thousands of listeners swing their arms in tandem with Townshend as they become air-guitar gods.

10:19: A "Tommy" suite is stretched into an inter-galactic epic, propelled by Townshend's hammering, wailing, sky-biting "Purple Haze" solo on "Underture." Nevertheless, it sounds anticlimactic after "Won't Get Fooled Again." Even better would have been "Love Reign O'er Me"; sadly, strangely, there were no numbers from "Quadrophenia."

10:38: The concert ends with Daltrey and Townshend performing "Tea and Theatre," a sad, tender reunion of mad creators from Townshend's blog novella "The Boy Who Heard Music." Spectators toast the grizzled, gracious comrades with a thunderous "WHO!!!," a thank-you for 33 years of maximum R&B.

7:32: Peeping Tom starts the evening with a bizarrely engaging, somewhat endearing blend of hip-hop and death metal. The eight musicians mix turntable scratching and Arabic/outer-space fiddle, a bashing wall of rhythm and catchy rapping ("You don't like anchovies/You actin' salty)." Dressed all in white, lead singer Mike Patton whips his body and voice like David Bowie imitating Sly Stone, or Rob Zombie channeling Cole Porter. Despite their impressive chops, they're a poor opening act; the only one thing they share with The Who is a middle-finger attitude.

It's been 40 years since Pete Townshend wrote "My Generation," unwittingly giving critics barbs with which to mock him decades later. "Hey, didn't you hope you'd die before you got old? So why don't you f-fade away?"

The Who haven't. Instead, they have kept coming back, long after promising to leave for good - even though by now half the foursome is in the grave.

So when Townshend and Roger Daltrey took the stage of the sold-out Wachovia Center Tuesday night for the first show of their U.S. tour, hanging in the air was the question of whether these two sexagenarians could even come close to mustering the majestic power that marked them as one of the greatest - and loudest - of rock bands.

The answer came as immediately as could be hoped in the form of "I Can't Explain," the eloquently concise expression of inarticulateness that - like "The Seeker" and "Anyway, Anyhow, Anywhere," which followed - harked back to the band's Mod years in '60s swinging London.

Both Daltrey and Townshend came out swinging. The former, dressed in blue jeans and blue-tinted, John Lennon-style wire-rimmed glasses, was barrel-chested and buff - and after putting down his cuppa tea, commenced to vein-busting bellowing. Brute physicality can't entirely make up for the once golden-voiced singer's loss of range, and even his lasso-like microphone tosses weren't as spot-on as back in the day. But the spirit was more than willing, and when "Won't Get Fooled Again" rolled around, he let out a mighty roar.

The gray-bearded Townshend hasn't aged so well, but his guitar-playing is in fine fettle, and he was ferocious on stage. He wore a striped skullcap that made him look like a cross between a mullah and a prison inmate - which brought to mind his status as a social pariah following 2003 child pornography allegations (he was never charged with a crime). And he played as if he had something to fight for, squeezing out jagged improvisational bursts of rhythm in the encore medley from Tommy and stepping into his propulsive power chords with gusto all night long. Would he windmill? Yes, he would.

The songs in the nearly 2 1/2-hour show spanned their career, though surprisingly, and disappointingly, the set was devoid of anything from the band's second grand rock opera, Quadrophenia.

There were well-chosen rarities, such as the '70s "Relay," and "Cry If You Want" from 1982's roundly despised It's Hard. And classic-rock landmarks, straight out of CSI: "Who Are You" (one of many songs in which drummer Zak Starkey proved himself a close approximation of, but no match for, Keith Moon) and "Baba O'Riley" (during which many fathers and sons, and a few fathers and daughters, sweetly sang, en masse: "It's only teenage wasteland!").

But what set the show apart among dinosaur-rock gatherings wasn't the high volume or the muddy sound mix or the spate of opening-night technical glitches. "See, the old stuff can sound just as crappy and unrehearsed as the new stuff," Townshend joked.

It was the amount of new music and the quality of it. A new Who album called Endless Wire is due out on Halloween, and the good news is it's not something to be frightened of.

Early on, the band - including Pino Palladino, ably and unobtrusively standing in for John Entwistle on bass, plus Townshend's multi-instrumentalist brother Simon, and the keyboard player John "Rabbit" Bundrick - played a seven-song excerpt from Wire & Glass, a rock mini-opera that will be included on Endless Wire.

Though it was new to them, the crowd stayed with it as if keyed in to Townshend's lines in "Mirror Door" about the artist's undying need for an audience: "If you don't hear me, how can I tell you? / If you won't listen, how can I speak?"

All the new material wasn't equally compelling: "Black Widow's Eyes" about the Stockholm Syndrome, was slow going. "Fragments," composed by a computer in tribute to Meher Baba, Townshend's late spiritual guru and the inspiration for "Baba O'Riley," came across as portentous. But two songs featuring Townshend's acoustic strumming as the backup for Daltrey's rough vocals were smashing stuff.

"The Man in a Purple Dress," accompanied by a video-screen backdrop of Head VI, a Francis Bacon painting of a pope with an exploding head, was all recalcitrant rage at the undeservedly pious. "How dare you be the one to assess me in this godforsaken place," Daltrey barked defiantly, on Townshend's behalf.

That unleashed anger was in contrast to "Tea and Theatre," a lovely, tender plea that was strong enough to close the show. And leave the crowd not booing, but Who-ing.