Cynical though it may sound, a tuner can get away with murder if it starts right and gets audiences on its side, or finishes with enough song-and-dance to convince them they’ve had a great time. Preferably both. The stage version of “Flashdance” manages neither. Considering the original famously climaxes with one of the most uplifting sequences in movie history, that’s some misfire. The strenuous production best serves to illustrate the gap between dance routines and show-driving choreography, between effort and achievement.

Recognizing that the original’s 95 minutes of close-up, softcore body worship dressed as female empowerment might not play well onstage in 2010, the plot, still set in 1983, has been given a shade more cohesion and grit for this expanded 155-minute (including intermission) revamp.

Most of the characters have been rejigged. The old lady encouraging heroine Alex (tough-talking Victoria Hamilton-Barritt) to follow her dream of giving up arc-welding and exotic dancing for ballet school is now Alex’s single mom, Hannah (spirited Sarah Ingram). Wannabe standup Richie is now Jimmy (Sam Mackay), who gets into debt with the drug-dealing strip-club owner, now renamed Dr. Kool (Ricky Rojas).

But any tension such tightening might have created is sapped by the addition of 10 anodyne rock-style pop songs, which lengthen rather than strengthen the proceedings.

As with “Saturday Night Fever,” the original was a dance musical, with songs on the soundtrack rather than in the characters’ mouths. That style is reproduced for the movie hits — the title track, “Maniac,” “Manhunt,” “I Love Rock ‘n’ Roll” — but not for the additional surprise-free mood songs that mostly tell us what we already know.

Jimmy and Nick get late solos, both dramatically pointless. Alex and her mom are already long into the shouting stage when they suddenly switch into a yelling duet, “You’re Not Done,” a move that generalizes everything thanks to lines rhyming “Wake up and look” with “Life’s not some storybook.” The same happens with “Don’t Stop,” Alex’s inevitable pre-coital power-duet with Nick (Matt Willis) which hits cliche overload with an obvious, up-a-gear key change and sudden orchestral-style finish flooded with wannabe-orgasmic purple lighting.

Still, that sequence at least builds, unlike the dance numbers. Choreographer Arlene Phillips works the good dancers very hard, but the energy goes nowhere as the numbers lack structure and shape.

The solo work is fast-moving and wildly acrobatic — bump-and-grind, leaps, stretches, isolations and wholly anachronistic body-popping and streetdance — but faced with groups, Phillips merely multiplies the moves. Neither she nor director Nikolai Foster can harness the energy to charge up the space or bring a number to climax; everything starts at full bore, and then just stops. Even “Nightmare,” a dream sequence that should be terrifying, is simply an angry, fast-forward recap of the plot thus far.

The decision to give so much dance to other characters — Alex can’t walk down the street without coming across gangs of breakdancers — also creates a serious problem: Alex now looks no different to anyone else.

Near impossible though it is to re-create (the original used Jennifer Beals plus five body doubles), the staging of the movie’s signature sequence has to make you believe Alex is extraordinary. But in contrast to the equivalent moment in the superior blue-collar ballet dream “Billy Elliot,” it simply doesn’t.

Phillips and Foster start with Hamilton-Barritt alone, but then bring on an entire ensemble for another repetitious routine, showing up the fact that, talented as she is, the ever-ready actress cannot cut it. Even when she’s won the place, the production team is at a loss to capitalize on what should be the emotional rush, leaving Alex and Nick looking awkward as a slow curtain falls.

The most impressive work comes from designer Morgan Large, whose inventive, multi-locational sliding-steel panels carve the space and create the atmosphere, scale and solidity the production lacks elsewhere. But coming out of a musical humming the sets suggests a show in deep trouble. Nostalgia for the title could keep the show afloat for a while, but only a complete overhaul with new creatives could turn this into a Stateside hit.

Flashdance — The Musical

Shaftesbury Theater, London; 1,338 seats; £55 $88 top

  • Production: A Christopher Malcolm, David Ian Prods., Steven Baruch, Tom Viertel, Marc Routh, Richard Frankel, Transamerica, David Richenthal, with executive producer Tom Hedley in association with Paramount Pictures and Diana Bliss, Broadway Across America, Douglas L. Meyer, David M. Milch, Mirvish Prods., Network Presentations, the Production Studio, James D. Stern, James Tod, Michael Watt presentation of a musical in two acts, music by Robbie Roth, lyrics by Robert Cary and Roth, book by Tom Hedley and Robert Cary, based on the Paramount Pictures film, written by Hedley and Joe Eszterhas, story by Hedley. Directed by Nikolai Foster. Musical direction, Dave Rose. Choreography, Arlene Phillips.
  • Crew: Sets, Morgan Large; costumes, Sue Blane; lighting, Howard Harrison; sound, Bobby Aitken; orchestrations and musical supervision; Phil Edwards; video, Ian William Galloway; production stage manager, Guy Ongley. Opened, reviewed Oct. 14, 2010. Running time: 2 HOURS, 35 MIN.
  • Cast: Alex Owens - Victoria Hamilton-Barritt Nick Hurley - Matt Willis Hannah Owens - Sarah Ingram Gloria - Charlotte Harwood Jazmin - Twinnie Lee Moore Keisha - Hannah Levane Joe, Harry - Russell Dixon Jimmy Kaminsky - Sam Mackay Dr. Kool - Ricky Rojas With: Ivan Blackstock, Myles Brown, Brendan Cull, Nicholas Gilligan, James Hall, Zoe Green, Kirby Hughes, Sia Kiwa, Andrew Spillett, Maria Swainson, Amy Thornton, Daniel Uppal, Robbie White. Musical numbers: Act 1: "Steeltown Sky," "One in a Million," "In Touch With the Beat," "High Art," "Maniac," "Half a Chance," "Twenty-One," "Totally Different People," "Manhunt" "Don't Stop," "My Next Step." Act 2: "I Love Rock 'n' Roll," "Experience," "You Can't Keep Me Down," "You're Not Done," "Gloria," "Wake Up," "Don't Stop" (reprise), "Nightmare," In Touch With the Beat," "Flashdance (What a Feeling)."