Who in their right mind wouldn’t haunt the library stacks if Kate Baldwin were assigned to the checkout desk? Teamed with Burke Moses in Arena Stage’s endearingly melodic revival of “The Music Man,” this quintessential Broadway songbird, with skin like peaches and voice like cream, ensures that we’re solidly in the corner of Marian the Librarian and the slick faker she guides to true love.

It’s evident in the performance by Baldwin — Tony-nominated for “Finian’s Rainbow” in 2010 — how she’s grown since making a memorable debut at Arena as Nellie Forbush in the 2002 “South Pacific.” Her soprano, wrapped around lilting Meredith Willson ballads (“My White Knight,” “Till There Was You”), has become an even more refined instrument, and her manner is more assured. In Moses, too, she has the partnership of a seasoned performer, giving a thoroughly appealing account of Harold Hill, the snake-oil salesman who smooth-talks gullible River City, Iowa, into his boys’-band scam.

With their contributions and Willson’s marvelous handiwork — the brassy “Music Man” is one of the best-built musical comedies of all time — it would be hard for a theater company to go wrong. And for the most part, director Molly Smith doesn’t. Assisted by gifted choreographer Parker Esse, master set designer Eugene Lee and savvy music director Lawrence Goldberg, Smith assembles as sturdy, moving and enchantingly sung a “Music Man” as you’re ever likely to come across.

It materializes, though, in the shadow of Smith’s revelatory “Oklahoma!,” which in 2010 opened the refurbished Fichandler Stage and established Smith, after a few tries and with varying success, as an important re-conditioner of classic American musicals. Whereas her “Oklahoma!,” filled with actors of color, showed us a new way to think about the extension of American opportunity, Smith’s “Music Man” merely reconfirms what a warmly all-American pleasure-machine this musical can be.

One sees how foolproof was the road map laid out by Willson — who wrote the music and lyrics and co-wrote the book of this 1957 show — when Smith and her creative team diverge from it. The faux pas here is the director’s attempt to confer some unnecessary notion of universality on the story, which is as redolent of one specific time and place as any depicted in any major musical of Broadway’s Golden Age. Willson, born and raised in Mason City, Iowa, based his River City on the town of his youth so totally that he took pains to note in an introduction to the script how vital was authenticity in any production.

“The humor of this piece,” he wrote, “depends on its technical faithfulness to the real small-town Iowans of 1912, who certainly did not think they were funny at all.”

The decision by Smith and costume designer Judith Bowden to update the look of the starchy River City-ites to something like the mid-20th century is a wholesale miscalculation. Willson’s point was not that this is Anywhere, U.S.A. Yes, it’s an idealized idea of a real place, but it’s a real place nonetheless, no less so than the Manhattan of “West Side Story” — which it bested for the Tony for best musical of ’57. And its values are inscribed in a particular age: this is a town thrown into five-alarm hysteria over what a pool table will do to the morals of its kids. While the desire to apply fresh varnish in 2012 is understandable, putting the River City teenagers in well-tailored jeans and denim jackets makes it seem as if they’re awaiting the arrival not of the Wells Fargo wagon, but Conrad Birdie.

Were this “Music Man” cast any less accomplished, the wardrobe might have amounted to a full-blown disaster. In this case, it’s only a distraction. (Although the getups in the finale for the Wah-Tah-Nyee girls are flat-out jokes, and not in the ha-ha sense.) Still, you know you’re in an especially good musical place when Marian’s mother, played here with oodles of elan by Donna Migliaccio, is this memorable, or the balletic town ruffian, Tommy Djilas, is handled with as much jete-ing panache as is displayed by Will Burton.

Architecturally, Lee has employed the most basic of set designs for the Fichandler, and it’s subtle and wonderfully adaptive. The floor of the in-the-round stage mimics the high-school gym where the townspeople meet. A hole has been cut in the middle for the execution of delightful hydraulic entrances, beginning with the traveling salesmen who rise to the stage as the crammed-in railway passengers of Willson’s brilliant proto-rap, “Rock Island,” recited to the rhythms of the moving train. (Lee’s set is, in fact, the revolutionary element here, allowing us to breathe the air of 1912 with nary a pianola or antimacassar in sight.)

The score is one of those weathered chests from America’s well-stocked musical attic that yield up treasure after treasure. And whether it’s cheek-tweakingly adorable Ian Berlin, offering up the hummable syncopations of “Gary, Indiana,” or the four supple members of the school-board quartet, blending high, low and in-between pitches to “Lida Rose,” the actors forcefully remind us of the inventive ways Willson used tempo and unusual sources, like barbershop and piano scales and Sousa-style marches, to tell this native story.

It’s fortunate, too, that Esse has found dancers who look like real kids, and not weight lifters or ballerinas, for the lithe choreography he applies to the great “Marian the Librarian” number, as well as to Willson’s one musical miscue, the god-awful “Shipoopi.”

As the 1962 movie with Shirley Jones and, more to the point, Robert Preston, enshrined for us on celluloid, “The Music Man” is a rhapsody only when Marian and Harold are in harmony. Let’s stipulate that no one will ever, ever out-Harold the peerless Preston. Man and role are eternally one. But any Hill who climbs the irresistible sermon song “Ya Got Trouble” as expertly as Moses does is a worthy inheritor. And with Baldwin in his arms, Arena’s got no trouble at all.

The Music Man

Music and lyrics by Meredith Willson, book by Willson and Franklin Lacey. Directed by Molly Smith. Choreography, Parker Esse; music direction, Lawrence Goldberg; set, Eugene Lee; costumes, Judith Bowden; lighting, Dawn Chiang; sound, Timothy M. Thompson; wigs, Anne Nesmith. With Heidi Kaplan, John Lescault, Barbara Tirrell, Nehal Joshi, Michael Brian Dunn, Justin Lee Miller, Rayanne Gonzales, Juliane Godfrey, Joe Peck, Lawrence Redmond, Sasha Olinick. About 2 ½ hours. Through July 22 at Arena Stage, 1101 6th St. SW. Visit www.arenastage.org or call 202-488-3300.