For musical theater fans, "A Chorus Line" remains a transcendent experience, exposing the sweat beneath the spectacle, the human cogs that bring the machinery to life. Applying '70s-style group therapy principles in a then-revolutionary context, the show spins a line of dancers auditioning for a Broadway chorus into a universal metaphor for anyone struggling for recognition in a competitive world. Its stinging irony is that even as their individual hopes, dreams and vulnerabilities are explored, the dancers are being groomed to join an assembly line.

After 15 years on Broadway and countless regional, touring and international productions over the past three decades, "A Chorus Line" has fostered lots of warm memories in lots of folks, and the show provides emotional jolts of recognition that go beyond mere nostalgia. At certain key points -- when the cast turns away from the upstage mirror to face the audience for the first time in the opening dance combination; the high notes in "At the Ballet"; the ensemble coming in on the chorus of "What I Did for Love" -- a visceral charge can be felt coursing through the audience.

What's missing here is ownership. Reproducing Bennett's staging to the letter, original co-choreographer Bob Avian has assembled an appealing cast of accomplished singer-dancer-actors. But while everybody works hard, no one quite dazzles. That seems dictated not by any lack of talent but by the fundamental limitations of the production's approach. Fitting into the established contours of existing performances rarely generates the same sparks as creating them from scratch. The actors onstage feel like topnotch replacements rather than originators. It's the sense of duplication -- albeit lovingly executed -- that keeps the revival from soaring.

That the show is satisfying despite those constraints testifies to the strength and honesty of the material. Much has changed in the 31 years since its premiere, notably the prevalence of this type of confession in popular entertainment.

Back in 1975, characters airing their personal pain, their sexual awakenings, adolescent traumas and murky family histories, their fears and frustrations, was a relatively fresh concept. A slew of talkshows including "Oprah" and reality television have since cemented emotional self-exposure in public forums as a pop-culture staple. Everyone is now dying to spill his innermost secrets, so the persistence with which director Zach (Michael Berresse) has to coax his aspiring chorus members to reveal themselves seems very much of another time.

Given that shift, it makes sense to retain the original 1975 setting. Any attempt to update the material likely would ring false (like the heinous 1985 Richard Attenborough screen version, which halfheartedly nudged the action into the '80s -- though that was the least of its blunders).

Meanwhile, the explosion over the past decade of "American Idol" and its brethren has popularized the elimination-and-selection process in ways that may help "A Chorus Line" find a new audience.

Seeing Bennett's exhilarating dance sequences again, his choreography exactingly restaged by original cast member Baayork Lee, it's inevitable to note by comparison how poorly dance is integrated into most Broadway shows now. Inevitably in a musical conceived by a former gypsy and culled from the experience of those unsung ensemble members, movement informs almost every scene -- and it's only in a couple of draggy spoken scenes that the show's wrinkles work against it.

The deft, almost invisible structure of James Kirkwood and Nicholas Dante's book poignantly mirrors the highs and lows of a chorus dancer's life -- discovery of the desire to dance; years of struggle; the tantalizing promise of a job; the transporting rush of performing; the cruel awareness of a looming expiration date; the wistful look back.

Set to the distinctly '70s sounds of Jonathan Tunick, Bill Byers and Hershy Kay's original orchestrations, Bennett's fluid compositions remain passionate and dynamic, with the cast almost reflexively falling back after each number into that line emblazoned on the memory of anyone who has seen the show.

Equally enduring are composer Marvin Hamlisch and lyricist Edward Kleban's songs: "I Hope I Get It" provides an opening that pulses with urgency and optimism; "Hello Twelve, Hello Thirteen, Hello Love" masterfully weaves multiple narratives into a collective rite of passage; "Dance: Ten; Looks: Three" is as tart a comic number as you could wish for; and "One" masterfully encapsulates both the glitzy showstopper and the subtext of individuality harnessed into robotic synchronization.

Vocally, the production mostly matches the original. This is one area in which the cast is allowed to put its own imprint on the material rather than simply carbon-copying the cast recording. Among standouts, Chryssie Whitehead as tone-deaf Kristine gives a daffy, distinctive take on "Sing!," while Mara Davi, with her sweet, sure voice and unguarded stage persona, does a gorgeous job on "At the Ballet." Also registering strongly is Jason Tam as Paul, who gets the show's most emotional passage as he relives the pain of growing up gay. Casting of Deidre Goodwin as brittle Sheila makes the traditionally white character into a more familiar proud black mistress of the quick retort, but Goodwin looks terrific and does imperious sass with flair.

The closest the ensemble piece has to a starring role is Cassie, the humbled former featured dancer looking to slip back into the chorus and negotiating the baggage of her history with Zach (played with crisp authority by Berresse). In her extended dance solo during "The Music and the Mirror," Charlotte d'Amboise doesn't surpass the memory of Donna McKechnie, who created the role, but her Cassie has a lovely, understated melancholy quality -- possibly informed by d'Amboise's professional history as a perennial replacement.

The design elements hold up brilliantly -- Robin Wagner's spare, mirrored set, allowing the aud to see itself as well as the dancers; Theoni V. Aldredge's costumes, full of subtle character details; and Tharon Musser's precision lighting, adapted here by Natasha Katz.

Whatever the merits or shortcomings of reproduction vs. reinvention, it's unquestionably a plus that "A Chorus Line" is now accessible to new generations of theatergoers. Whether or not the show sticks around another 15 years, its unique place in musical theater history and heartfelt insights into the dedication and sacrifice of its below-the-title workers make it deserving of a permanent home on Broadway.
 
Music direction and supervision, Patrick Vaccariello. Choreography restaging, Baayork Lee. Sets, Robin Wagner; costumes, Theoni V. Aldredge; lighting, Tharon Musser, adapted by Natasha Katz; sound, Acme Sound Partners; orchestrations, Jonathan Tunick, Bill Byers and Hershy Kay; vocal arrangements, Don Pippin; music coordinator, Michael Keller; production stage manager, William Joseph Banks. Opened Oct. 5, 2006. Reviewed Sept. 30. Running time: 2 HOURS, 5 MIN.
 

 
With: Michelle Aravena, David Baum, Mike Cannon, E. Clayton Cornelious, Nadine Isenegger, Lorin Latarro, Grant Turner.