There are a finite number of "Great Moments in Rock Music." But they're an elusive lot--like lists of good movies, it's tough to order these turning points into a manageable form. Defining them isn't any easier. Their levels of meaning are subjective: the physical and ethereal, instants tangible and intangible, chords. lyrics, album covers, whatever. Even subjective lists, though, are valuable as structural indicators, direction finders.

So. There's Jeff Beck's introduction to "Over, Under, Sideways, Down;" Ray Davies' integration of "Land of 1000 Dances" into his archetypal "Top of the Pops;" the musical moment between "Jumpin' Jack Flash" and "Honky Tonk Women," which signified the end of mainstream Sgt. Pepper experimentation; "Lola." Pithy moments that, like good imagist poetry, are form, substance and implication in the instant they are heard. Take Peter Townshend's "My Generation." The singer's stutter says as much as the lyrics and says it better.

Now, there's The Who's new Quadrophenia. It's too soon to grant it Great Moment status, but it certainly extends Townshend's credentials as an innovator, and it sure beats Tommy all hollow as an opera. The album's advantage is that it retains its committment to its music. Tommy's failure was due partially to the absurdity of its scenario and also to its author's over-committment to operatic form--to the detriment of the music. The resulting confusion produced a remarkably uneven work. It had little depth and it was moralistic, even melodramatic.

Quadrophenia is much more luced. Just as it addresses itself to the rock in "rock opera," it draws on a readily recognizable context: the Mod-Rocker wars of the middle sixties. From which wars sprung The Who, among many. While Tommy's hollow symbolism may have destroyed its viability, Quadrophenia's Jimmy is accessible thematically and physically, as far as two dimensions will carry him. The picture book insert not only fleshes out the scenario, but gives the listener an almost tangible hero. At the same time there is that hint of Townshend mysticism. The idea of fusing the band's personality into one character serves as anchor and springboard.

Each of Quadrophenia's successes points back to the real people and locations under discussion. Its scope is limited, then; it has little to say thematically. Only one of the four themes (Peter Townshend's, in fact) is explicitly moral, and the weakest, lyrically and musically, ending the opera with a piece of simplistic fluff called "Love, Reign O'er Me." In the main though, aside from Quadrophenia's socio-historical-contextual significance (which is nothing to dismiss), whatever statement it makes is one of "stance."

And stance translates onto the stage much better than morality. The Who in concert have always been a band of stance. They're responsible for rock's first steps towards the theater. Those smashed guitars, battered amplifiers, twirled microphones, and general onstage uglinesses have done more for, say, Alice Cooper's stage show, than is generally thought. The vital difference, of course, is that The Who have something to translate (this is not l'art pour l'art), namely lower class punk arrogance and good old teenage hostility. Townshend has expended the bulk of his creative energy on his working class contemporaries, and succeeded primarily at proving that he's a punk at heart himself. He passes that adolescent arrogance on to his band, and they hand it on to us (and do you have any idea of the power behind "Won't Get Fooled Again?" I mean hostile, chair-throwing, amp-smashing Power?), which is something the Stones cannot do adequately, because there simply aren't enough punks in the band.

This is the core of Quadrophenia--punk arrogance, hostility, basic lower class frustration. Which is why these songs perform so well in concert. Because their autobiographical nature, really a secondary feature of the album, becomes dominant. The two-thirds of the opera that are performed is a strong two-thirds, even though two of the four themes are eliminated. Townshend programmed some sound effects for the stage and added two small banks of PA amps to the back of the hall, a real stroke of genius, because filling Boston Garden with sound is no picnic. They filled it.

The songs themselves were faithful renditions, harsh, chord-oriented, charged tunes, that did, it's true, tend to run together a bit. I suspect the majority of the crowd was unfamiliar with the work as a whole (requests for Tommy were shut off with a brusque, "Where've ya been?"), and that hurt the performance some. Certain things were revealed: Townshend is a conservative guitarist--underneath the windmilling is a man who plays crisp licks and lines and is a master of transitions. He alternates finger-picking, chording and single notes with intelligence and grace, particularly in "I'm One," and the opening of "5:15." He plays with power, though. Live versions of "Bell Boy" and "The Punk Meets the Godfather" were exercises in controlled violence--loud, vehement, essential--sinple progressions and lines manipulated through pure volume to extract peak effect. Bassist John Alec Entwhistle continues to anchor the band. Dour, rigid, dressed in black, surrounded by performers, he receives little attention. Yet often as not he's playing as much of the lead as Townshend; his progressions on "The Real Me," and his work with Keith Moon on "Drowned" were truly stunning. Roger Daltry is a puppet, a helpless dancer. Programmed to march, twirl mike cords and pose with his hands clasped over his head, he's at a consistent loss for something to do. He may still suffer from an unfamiliarity with his material. In general his range, though not infinite, enables Townshend to escape with his own transitions of mood. The openings to "I'm One," "Sea and Sand," as well as "Love, Reign O'er Me" demand a vocal vulnerability that Daltry is always up to. Moon? Well, Keith clowned from beginning to end, played ubiquitous drums, sang "Bell Boy," and wore headphones that kept the whole band in time.

The catchword for the show is chaos. The Who tumble up the stairs and onto the stage--unlit, save for a blinking reproduction of a Civil Defense fallout shelter sign. No ceremony, no circumstance, no introduction. There are four songs to warm up, Quadrophenia, then three more songs. The warm-ups are a smattering of history. And they are run off like copies--"Can't Explain," "Summertime Blues," "My Wife," and "My Generation." Their essence is a fifteen second repetition of those windmill chords Townshend has made famous. They succeed like calisthenics--Daltry twirls his mike, Townshend does his splits, Moon acts like a three year old, Entwhistle does nothing, and the audience sits on its hands.

There's nothing difficult about these songs; they've got volume, crispness, precision, but no life. In fact, nothing really happens until midway through "My Wife," when Townshend finds a riff he can work on, Moon and Entwhistle lock into a solid rhythm and Daltry sees fit to chant "keep on movin'" over the top of it all. It brings a noticeable surge in intensity. "My Generation" is similarly structured and similarly extended, but awkward because it no longer incorporates pieces of Tommy. Townshend resurrects it by adding a simple solo to the break.

The show doesn't really start until after Quadrophenia. "Won't Get Fooled Again" is dedicated to the Montreal Police. It's a complete version with synthesizer pre-recorded onto a tape. This is the recognizable, post-Tommy Who that everyone obviously had been waiting for. It's not safe to underestimate this song's power as performed. With all the arrogance, frustration and simple sneering punk hostility The Who bring to the stage, coupled with the substantial amounts of same written into the song...well, there was an obvious emotional peak. "Pinball Wizard" initiated hysteria--as much because it's from the by now deified Tommy as for any musical worth. It was well done, and faithful, with Daltry finally in good voice and Townshend alternating subtleties and musical invective. "See Me, Feel Me" is the closing number. It is Tommy's strongest song and, as a finale, is head and shoulders above "Love, Reign O'er Me." Done live, as an obvious climax, it's a second emotional peak.

There were two boys in the row in front of me, Second formers at Groton, accompanied by a teacher. All I remembered was the trouble I went through to get off campus and into Boston in 1968 to see Cream in a theater that is now middle income housing. And then it struck me. They were five years old in 1965, when the Who released the songs that justified their existence on that stage, that night, for me. Quadrophenia's success is contextual, and The Who in concert are still playing upon sentiments from that context. The kids in front of me couldn't have known that. But they knew what they liked. I think Rock and Roll is here to stay.