MUSIC REVIEW THE WHO. The old folks are alright. At Jones Beach Theater. Sunday night.

MIDWAY through The Who’s performance Sunday night at Jones Beach Theater, a fan urged Pete Townshend to smash his guitar — a concert ritual in the band’s heyday three decades ago.

Townshend’s blue eyes narrowed into contemptuous slits. “Do you know how old I am?” he snapped. (He’s 55.) “How old are you? If you want to break it up, you come up here and break it up.”

As Townshend obviously understood, even the most symbolically potent gestures can become buffoonery in the hands of aging rockers on the reunion circuit. This is particularly the case with a band such as The Who, which was as famous for its raucous antics as for its raucous sound.

But apart from Roger Daltrey’s tendency to swing his microphone cord a few too many times, there was nothing laughable about The Who’s performance. Mean and lean, backed only by drummer Zak Starkey and their longtime guest keyboardist, John Bundrick, the three surviving bandmates put on an explosive show that was laden with the anarchic energy of their youth.

The band hit the ground rocking with “I Can’t Explain” and kept up the pounding pace with a cocky “My Generation,” an extended, funked-up “Magic Bus” that recalled their incendiary “Live at Leeds” recording, an anguished “Behind Blue Eyes” and a synth-twittering “Baba O’Riley.” The band members’ lined faces and ragged voices gave the refrain, “teen-age wasteland,” extra pathos — they sang about the ravages of youth with the knowledge of someone who’s been there and paid the price.

In between were a few rarities, including “I Don’t Even Know Myself,” a strutting blues-rock piece off “Lifehouse,” the rock opera that Townshend recently finished after a 29-year hiatus.

Apart from a perfunctory “Pinball Wizard,” the band spun out most of the songs with extensive riffing, most of it from Townshend, who pounded and bent his notes at the end of each windmill arm move into dazzlingly swift, staccato figures. Dressed from head to toe in black, with his hair cropped like a monk, the gaunt Townshend looked like an undertaker, but his leaps and lunges harked to his glory days.

Apart from overdoing his microphone cord shtick, Daltrey was a commanding figure. His range isn’t what it used to be, but his gritty voice remains powerful — and his polished torso, which was amply displayed, is as gorgeous as ever. His howling harmonica shuffles were nothing to sneer at, either.

The stoic Entwistle left the drama to his fingers; his lunging, sputtering bass solo made “5:15” a highlight. Starkey, the son of Ringo Starr, pummeled impressively; while he has none of the riotous charisma of The Who’s original, inimitable drummer, the late Keith Moon, he kept the band at an appropriately punishing gallop. Bundrick’s rollicking keyboards kept the sound from bogging into density.

Apart from his outburst over the invitation to smash his guitar, Townshend was affable and effusive, gushing about how Jones Beach Theater is “just about my favorite stage in the world.”

And before the encores, Townshend took his guitar, aimed it at the stage floor with the precision of a woodchopper about to wield an ax at a tree trunk, and smashed it to bits. It was a slow, careful gesture, filled with ritual force but devoid of any pretense of spontaneity. I’m doing this for you because you want it, but not because the show needs it, Townshend’s movements implied. He was right.

Who are you? From left, The Who’s John Entwistle, Roger Daltrey and Pete Townshend

Newsday Photo / Bill Davis