The Who may not be the “greatest rock ’n’ roll band ever,” as they were introduced at the Meadowlands Arena on Sunday night, but they are definitely one of the most influential and popular bands in rock history (a fact attested to by their sell-out performance at Shea Stadium — one of two this week — tonight).

At the arena, the Who opened its two-hour set with the song that put them on the rock map, “My Generation,” a song and a style that inspired the much later punk rock movement, as well as two generations of aspiring teen rockers in basements and garages on two continents.

The enormous influence and appeal of the song and the style, a style that remains basic to the Who’s live appeal, however much they may have abandoned or outgrown it in the recording studio, is that they transcend the boundaries of music, in the conventional sense. More than any other pop group before them, the Who rejected conventional music. They didn’t play music, they played rock.

Roger Daltrey didn’t sing — he screamed, stuttered and shouted. Pete Townshend didn't play guitar chords, he slashed them out with a windmilling arm, making them sound like artillery barrages. The late drummer Keith Moon didn’t keep time, he bashed away as if warring with Townshend’s guitar volleys.

Only the most astute aspirants to rock noticed that bassist John Entwistle maintained the basics of musical coherence and structure. After all, the focus was on Daltrey whirling his microphone in lasso-like arcs and Townshend leaping about and windmilling his guitar.

Almost two decades later, the focus on stage remains the same. Except that Townshend doesn’t end the night by smashing and burning his guitar. And the members of the Who are all way past 30, not teenage punks. And the sounds they make — those once defiant, anarchic cacophonies — are now part of the accepted musical vocabulary of rock. In fact, many of their songs are now considered rock classics.

In concert, the Who are faced with the problem all the older classic rock bands face: How to balance new material with the old classics. The Who did it by presenting most of the new material — judiciously broken up with older songs — during the first of their two hours on stage.

They did the title cut from their new album, “It’s Hard,” only after Entwistle had done a couple of his songs, including “Dangerous” from the same album. Audience reaction was only politely enthusiastic.

It was much more enthusiastic when they reached back for “Behind Blue Eyes” and “Baba O’Riley.” On “O’Riley,” many members of the sell-out crowd joined Daltrey on the wailing chorus: “Teenaged wasteland.”

Townshend has always been considered some kind of rock intellectual heavyweight, although his solipsist lyrics crumble under scrutiny, and I suspect his champions indulge in the sophistry of equating his musical gifts with his verbal. His rendition of “I Want to Drown” followed to confirm my view.

The words to “Athena” — “She’s a girl/She’s a bomb?” — yield little Homeric wisdom either, but the song is the Who’s current pop hit and was greeted ecstatically by sing-a-longers.

“Who Are You?” — that most cleverly egotistical song — was given a bright, almost bouncy reading, with Entwistle and Townshend chiming the ironic question in falsetto, Daltrey running in place as if training for the New York Marathon, and Tim Gorman providing tinkling keyboard trills. (Gorman is the only added performer on this tour, a departure from the large supporting cast of the 1980 tour.)

Pete Townshend has probably inspired more air guitarists than any other rock star, and they appeared in profusion, whirling their arms, as the Who launched into “Pinball Wizard” from “Tommy,” Townshend’s celebrated rock opera.

Two more “Tommy” excerpts followed, with the finale’s words “Looking at you, I hear the music…” accompanied by that latest de rigueur rock concert assault on the senses, blinding lights aimed at the audience. After the lights subsided, the classics continued with unabated rock energy. Townshend even showing off a Chuck Berry duck-walk.

Daltrey, incredibly, seemed to pick up steam as the second hour ticked on, exulting through “Substitute” and bringing the proper anthemic passion to “Won’t Get Fooled Again.” He returned in the encore for a spirited “Summertime Blues,” finally relinquishing the vocal chores to Entwistle for the closing number, a surprisingly gritty “Twist and Shout.”

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This tour has been billed as the Who’s last, or what Daltrey calls “our first last tour.” Townshend has said the group is breaking up, that other, younger groups are taking up where the Who left off. He’s probably right.

But the Who has left its mark on rock, defining much of what has become the basic vocabulary and attitude of the music. And, judging from their performance at the Meadowlands, they can still rock their classics with conviction.