ONE OF THE CURIOUS things about "A Chorus Line" is how unmemorable the dancing is, for a show that's all about dancers.

After two viewings, I find it hard to conjure up a single characteristic image or sequence from the dance numbers. Oh yes, something comes to mind. Exactly what the title suggests - symmetrically arrayed legs and torsos flicking and kicking away to beat the band. It's exciting, it's infectious, it's irresistible, in fact. But distinctive it's not.

Not that this makes much difference in the end. The production, inseparable in this case from the material of the show itself, is so deftly manicured, so accurate in its reckoning of audience soft spots, so unremitting in gut appeal, that it is impervious to its own flaws. A story that strains credibility, souped up dialogue trying to pass as "natural," an essentially cruel dramatic premise, a pedestrian score and indifferent choreography - none of this seems to lessen the show's impact.

"A Chorus Line" - quite possibly the musical blockbuster of the decade - may be a more subtle achievement than even its admirers realize, in the way it overcomes limitations no weaker show would survive. But is it what it's cracked up to be?

"Courageous," "compassionate" and "shattering" are the kinds of descriptives that repeat themselves from review to review. "Bowls you over with heart, truth and excitement" exclaimed one critic; "An affirmation that a musical can touch unexpected depths in the human heart" exulted another. Others hail its "originality" - "Recharges the musical comedy form!," for example, or "A major event in the development of the American musical theater." Joseph Papp, whose entrepreneurial daring made "A Chorus Line" possible, speaks of its "universal" significance and its "documentary character." Cast members tell us how being part of the show changed their lives.

In short, it's not enough to credit "A Chorus Line" with being an enormously effective musical. One must, it seems, regard it in reverential awe as a landmark, and a profound, revolutionary landmark at that.

But if you step back from the hoopla, you may find nothing in the show itself to support such claims, though you may enjoy yourself mightily for the evening. The success of "A Chorus Line" is more simply attributable to its splendid basic concept, shrewd packaging, a high professional gloss and a lack of serious competition.

The show presumes to let us witness a theatrical audition in the raw, a brilliant stroke in terms of structural format. But then the audition, quite unaccountably, turns into a mass confessional, each of the "gypsies" peeling off veil after veil of psychological insulation. What director in his right mind, no matter how committed to Stanislavskian principles, would waste his time probing the inner selves of a bunch of hoofers who are destined, as the show's own conclusion demonstrates, for roles utterly devoid of individuality?

The revelations, such as they are, introduce us to as perfectly stereotyped an ensemble as any World War II movie platoon of GI buddies - the Jew, the Italian, the Irishman, the Negro, the WASP, and so forth. In "A Chorus Line," the mixture is updated and so are the autobiographical cliches - now we get sexual misadventures in place of Dear John letters - but the idea is the same.

Much has been made of the origin of the show in a series of tapes director-choreographer Michael Bennett made with fellow dancers, recording their life histories and intimate concerns. Certainly there are semblances of reality in "A Chorus Line" - all stereotypes derive their interest from roots in actual experience. But if you listen carefully to the dialogue and the lyrics, you'll discover that reality has been carefully tailored to fit the needs of entertainment, and that everything in the show is calculated to ring a particular emotional chime at a particular instant, whether it accords with dramatic "truth" or not. The most "poignant" bit in the script, for instance - Paul's divulging of his homosexual tribulations - is cunningly engineered to arrive as a preparatory foil for the finale.

The story, moreover, keeps tripping itself up on its own "philosophy." Zach, the auditioning director, says he wants to get to know all the dancers as people, which is why he interrogates them so remorselessly, but he comes across as a sadist and a louse who couldn't care less about their individual fates. The show tries to celebrate the ordinary, to make heroes of the poor slobs who give their last ounce to hoofing for sheer love of it. But after showing us what special people they are beneath the collective anonymity, it condemns them all to the faceless uniformity of the chorus line.

This isn't tragic irony - it's a confusion of values. An assembly-line worker may be an outstanding human being; that doesn't ennoble his task. In "A Chorus Line," Cassie the chorine knows she can't be a star, so she just wants a chance to dance in the chorus. Fine. But the show turns her into a star, which is a sentimental falsification - she's too special to be ordinary, and too ordinary to be special, but in "A Chorus Line," she can be both at once.

As for the choreography, it's just what Agnes de Mille called it - "very paltry." There's nothing original or fresh or inspired about it. All the platitudes of jazz and tap and ballet are drawn upon to furnish a serviceable dance continuity without a trace of creative personality.

Yet the show works, like nobody's business. Its victories are on other levels - the seamless momentum of the staging, the relentless energy of the performances, and the manipulative efficiency of the sob-story technique. In a way, "A Chorus Line" is a testimonial to the power of hype - it shows how well it works.