No wonder things got so botched with that MTA strike. If only the weather hadn’t been so cold, a randy outdoor picnic – with the help of a tipsy secretary and a batch of hearty Eisenhower-era show tunes – would have patched things up in no time.

No, you probably don’t go to “The Pajama Game” for insight into backroom labor politics or for workplace dating tips. (If your female employee spurns your advances, keep at it. She’s just playing hard to get!) You go for foursquare Hit Parade staples like “Hey There” and “Hernando’s Hideaway,” preferably delivered by a great-looking, great-sounding cast. And by those standards, director-choreographer Kathleen Marshall’s meat-and-potatoes revival gets the job done. She takes no chances in tackling the 1954 musical and achieves workmanlike – if occasionally humdrum – results.

Ms. Marshall moves speedily through George Abbott and Richard Bissell’s paperthin but pleasant story (streamlined by Peter Ackerman), in which romance threatens to derail labor negotiations and vice versa at the Sleep-Tite pajama company. Thrust into the Allen Toussaint role is Babe Williams (Kelli O’Hara), a tough-as-nails negotiator who still kisses her dad on the forehead, while hunky superintendent Sid Sorokin (Harry Connick Jr.) has a take on “labor relations” that includes a different sort of relations with Babe.

Mix these two up with a jealous efficiency expert (Michael McKean) and a passel of musical-comedy stock characters – the sexpot in tomboy’s clothing, the sassy receptionist, the avuncular old salt, the grumpy old salt – and you’ve got a dependable framework for the punchy, tune-filled score by Richard Adler and Jerry Ross (with some alleged help from the team’s mentor, Frank Loesser).

The somewhat creaky plot notwithstanding, “The Pajama Game” actually had a few innovations to its credit when it premiered in 1954 – specifically, a notably laissez-faire attitude toward premarital sex and plenty of cool/hot/weird/captivating choreography by a 26-year-old chorus boy named Bob Fosse.

But with the former now passe and the latter jettisoned for Ms. Marshall’s own choreography, the story needs to chug along with the well-oiled precision of the conveyor belts ferrying plaid and polka-dot pj’s across the stage. (Derek McLane’s crisp set and Martin Pakledinaz’s pastel-heavy costumes lend the production a satisfyingly retro feel without overdoing it.) In other words, it needs someone like the famously disciplined, no-nonsense Abbott, who also directed the original.

Ms. Marshall isn’t there yet. Perhaps her experience as artistic director of the dependably hands-off Encores! concert series has made her a bit gun-shy. Except for shuffling some material among the ladies and conjuring up a blissfully out-of-nowhere showcase for Mr. Connick, she has helmed a “Pajama Game” that could have been at home on Broadway 52 years ago. But she lacks the interpretive discipline to shepherd each set piece and musical break into a unified whole. The entire supporting cast degenerates into an every-character-actor-forhimself morass, with only Peter Benson’s skittish, pronoun-mangling Prez and Mr. McKean’s short-tempered Hines emerging from the free-for-all.

It may have been Fosse’s Broadway debut as choreographer, but Abbott knew talent when he saw it, and the show’s dance breaks were stretched out to accommodate Fosse’s talents. Ms. Marshall struggles to fill these extended stretches with sufficiently interesting steps; each sequence has about two ideas too few, and spry performers like Joyce Chittick (in a modified version of the role that launched both Carol Haney and Shirley MacLaine) are forced to essentially mark time for too long. The worst offender is her “Steam Heat” staging, which adds a bit of eye candy and not much else.

Somewhat surprisingly, Ms. Marshall is most successful with one of the show’s trickiest components – the central romantic pairing. Like other musicals of the time (“Promises, Promises,” “How To Succeed in Business Without Really Trying”), “The Pajama Game” has a smirking take on workplace sexual politics that doesn’t wear particularly well. Rather than hide behind an ironic gloss or pass anachronistic judgment, she shrugs her shoulders and brazens it out – and the material just barely supports the decision.

Ms. Marshall gets a fair amount of help on this score from her two charismatic stars. Mr. Connick’s creamy baritone has taken on a welcome pinch of grit since his boy-wonder days, and his beanpole physique has gone through a considerable revamp. (The audience at one recent performance emitted Tom Jones-level squeals during one shirtless scene.) And while he may be not entirely comfortable during the comedy scenes, bear in mind that the part was written for John Raitt, who wasn’t exactly a barrel of laughs.

Mr. Conick is well-matched in Ms. O’Hara, a rare high point in works like “Dracula”and “Sweet Smell of Success” who finally landed a role worthy of her in “Light in the Piazza.” Here she gets to trade in her ethereal soprano and belt out up-tempo numbers like a modern-day Merman, and she manages the shift in tone with remarkable success. The sexual tension between her and Mr. Connick is fairly resistible early on, but by the time a dishabille Babe whips up a Western omelet near the end of Act I, the two have made their case to each other and to the audience.

But those pesky labor troubles throw a wrench into things, and poor Babe calls the relationship off just in time to miss the production’s crowning achievement. For reasons not worth getting into, Sid is forced to seduce the mousy Gladys (Megan Lawrence, who’d gnaw her own arm off for a laugh, and falls just short of doing so). Gladys happens to know a certain “dark secluded place,” and wouldn’t you know it? Strait-laced Sid just happens to have a gift for sidling up to the piano and banging out a jazzy reimagining of “Hernando’s Hideaway,” complete with a Creole-inflected verse or two.

This is an absolutely gratuitous addition to showcase Mr. Connick. And you know what? It’s good. Nearly every number in “The Pajama Game” may qualify as a Broadway chestnut, but an alarming number serve no narrative purpose. “Steam Heat” is in because Fosse could work quirky wonders with it, not because it has anything to do with anything happening on the stage. Same with “Her Is.”

Given this ad hoc quality, if you have a leading man who can ignite the joint, why on earth wouldn’t you set him loose? Maybe the mirror placed over the piano keys to display Mr. Connick’s hands is a bit much. But there are worse crimes than hitching your show to your leading man’s extensive extracurricular gifts. (Less successful are Ms. Marshall’s and Mr. Adler’s efforts to rectify the disparity in music for Sid and Babe necessitated by original star Janis Paige’s vocal deficiencies: An Act II duet for the lovebirds fizzles, one of two “trunk songs” that have been added to negligible effect.)

The bottom line is that “The Pajama Game” works, even when the supporting cast runs amok and the dances are only soso. Roundabout has taken some of its musical revivals in very suspect directions (“Follies,””The Boys From Syracuse”), and it’s to Ms. Marshall’s credit that she knew to leave well enough alone. If you’re going to “fix” a show, make sure it needs fixing. Unless you have Harry Connick Jr. and a twirling piano. Then change whatever you like.

Until June 11 (227 W. 42nd Street, between Broadway and Eighth Avenue, 212-719-1300).