The question leading up to Saturday night's Tweeter Center performance by The Who was: How significant is the loss of John Entwistle, the revered bassist who died on the eve of the band's current U.S. tour at age 57? Not that significant, judging by Saturday's sold-out concert.
The absence of Entwistle's hulking, stoic presence was no doubt felt by many in the audience. After all, The Who has been visiting the Delaware Valley since Lyndon Johnson was president. But once the group's two remaining charter members, Peter Townshend, 57, and Roger Daltrey, 58, got it going, there was little, sonically speaking, that was different from past Who concerts.
It took the two rock icons very little time to get things cranked to an ppropriately high level. With them leading the way, the band's opening sequence - traditional set-starter "I Can't Explain" followed by fellow early-period signatures "Substitute" and "Anyway, Anytime, Anywhere" - set the evening's high-energy, high-decibel agenda.
As always, the two icons supplied most of the musical and visual focus.
Daltrey's vocals have lost little through the decades. His voice has aged nicely, and there's a richness of tone that has come with maturity. He remains able to summon an impressive amount of fury and power with his still formidable pipes. His personal tour de force was the gripping, near-operatic reading of "Love Reign O'er Me," the lyrics of which seemed to emanate from the greatest depths of his soul.
And, of course, there was the scream-for-the-ages that ignites the incendiary ending of "Won't Get Fooled Again,"the anthem that is arguably the greatest set-closer in rock history.
Neither has Daltrey's ability to command a stage diminished with time. His defiant posturing, steely blue-eyed gaze and trademark microphone cord twirling were constant reminders that he was one of the people for whom the phrase "rock star" was coined.
Townshend, was likewise mesmerizing. His jittery hard-rock guitar supplied a good deal of the performance's ferocity and sheer voltage. As he did during the band's last stop in Camden two summers ago, Townshend provided several key moments with his soloing. Foremost among these was his gloriously frenetic and aggressive fret work at the end of "Bargain."
He also entertained with his bag of stage tricks, including uncoordinated spins, jumps and bends, and signature "windmill" style of playing chords.
But as typically on point as Daltrey and Townshend were, they couldn't have pulled it off without their stellar supporting cast.
One can only marvel at the jobs turned in by Entwistle's spur-of-the-moment replacement, the melodically monickered Pino Palladino, and drummer-since-the- '90s Zak Starkey. Both served well their predecessors' legacies.
Palladino, whose sure-handedness belied the fact he had about 72 hours to learn the entire set, was excellent as he sometimes recreated, sometimes merely suggested, Entwistle's rumbling, athletic bass parts that provided the crucial bridge between between Townshend and original drummer Keith Moon, who died in 1978.
His defining moment Saturday came during the bass breaks in the middle of "My Generation." To the encouraging cheers of the crowd, Palladino scored with a series of dead-on runs that served as a fine tribute to the deceased rocker, as well as confirmation he is up to the daunting task of filling in for a true one-of-a-kind musician.
Starkey, son of Ringo Starr, once again captured both the sound and spirit of Moon's roiling, bashing style with an almost supernatural degree of accuracy. Keyboardist John "Rabbit" Bundrick and singer-rhythm guitarist Simon Townshend (Pete's brother), ably filled out the sound.
Speculation is already rife this will be The Who's final tour. If so, the band can retire from the road knowing they left the Tweeter audience with memories of a group whose greatness never faded.
As if The Who's turn wasn't enough, there was opening act - and fellow British rock god - Robert Plant.
Plant, the lead singer of Led Zeppelin, thrilled the crowd with a set that combined songs from his new CD, "Dreamland" with Zeppelin classics.
The former included a wonderful reinvention of the '60s blues-rock classic, "Hey Joe," which was far more meditative than Jimi Hendrix's benchmark psychedelic-blues version, and an equally re-imagined "Darkness, Darkness," a 1960s "FM" hit for the Youngbloods.
Among the latter tunes were a reading of Zep's acoustic masterpiece, "Going to California," that electrified the audience, an equally stunning "Babe, I'm Gonna Leave You" and a bone-shaking "Four Sticks."
Like Daltrey, Plant seems to have figured out how to keep the ravages of time from his vocal cords. His strangled blues yelps and throat-shredding rock workouts proved he is an artist who still has plenty to offer beyond cheap nostalgia.
Together, the two acts combined for as memorable a night of classic rock the Tweeter Center has ever seen.
Sent by David Rubinsohn