With 46 cast members, Geva Theatre Center's irresistible production of Meredith Willson's 1957 musical, "The Music Man," is its largest in nearly 40 years of professional theater in Rochester. It's an exercise in just how happy a non-stop hullabaloo can make an audience. Mark Cuddy's affection for the material is evident in his direction of the sunny story of a con artist who finds love and redemption even though he isn't looking for them, and who also gives the stodgy town of River City, Iowa, new life. It's an all-American story about the surprises encountered in the pursuit of happiness, and is designed to make you open your heart to all the things a post-modern outlook sneers at. "The Music Man" is going to win you over because what it says about last chances is deeper than easy irony, especially when it's portrayed with quick-stepping high jinx and scintillating good spirits. When it comes to this particular hokum, sign me up with the rubes.

Traveling salesman Professor Harold Hill (Rochester native John Bolton) is a free-spirited rascal who is always reinventing himself to fleece the suckers. If it also means seducing a town's most desirable young woman, so much the better. This time the raffishly charming Hill is selling boy's bands. Once he convinces the locals that the town's new pool table is the first step on the road to degradation, it won't be long before he pockets the take from instruments, uniforms, and instruction books, and grabs the first train out of town. But he fails to reckon with town librarian Marion Paroo (Eastman School of Music graduate and Lotte Lenya Competition prize winner Analisa Leaming).

The story is familiar enough - decent small-town girl reforms city slicker as both resist the mutual attraction but eventually find true love - but it works here because Cuddy and the cast treat it as if it matters. Musicals often create a make-believe world where what we wish for comes true, but it wouldn't be possible without the singing and dancing, especially when they're this good. Leaming in particular has a lovely, expressive voice in such songs as "Good Night, My Someone" and especially "Till There Was You" that conjure up the sweet simplicity of love ballads from the early 20th century. The ensemble singing in such numbers as "Iowa Stubborn" and "The Wells Fargo Wagon" is rich and full.

Amidst all this, Cuddy dodged a bullet. He moved the play originally set in 1912 to 1957 because, as he explained, "It's better set in the time [Willson] wrote it so we can enjoy a sense of nostalgia for a period that we can relate to." Sorry, but that's balderdash. Does that mean we also have to set "Oedipus Rex" in the 1950's because none of us remembers ancient Greece? The move results in small but jarring anachronisms as lyrics go racing by with references to largely forgotten demijohns, the race horse Dan Patch, and the joke book "Uncle Billy's Whiz-Bang." The good news is that most of the performances and the high-energy dancing to choreographer Peggy Hickey's 1950's-style balletic Broadway choreography soon make the update irrelevant.

The first act focuses almost entirely on Harold Hill as he wins over the town, but the second act is more introspective as Hill and Marion struggle to figure out what they truly want. Leaming's performance is suitably straightforward, but we have to see Hill change. John Bolton has all of Hill's bravura moves down pat, but in the first act he never fully projects the airy certainty and glib self-control that define the con man. In the more realistic second act, that half step of distance helps to ground him more believably.

Skip Greer as the comic villain, Mayor Shinn, is effectively bombastic and bumptious, although Jennifer Smith as his wife, Eulalie, lacks the character's mock superiority. As a result, the Mayor isn't as sharply defined as he might have been. Similarly, Cass Morgan's failure to invest Mrs. Paroo with humor and determination weakens the important but loving tension between Marion and her mother over the daughter's refusal to land a husband.

Don Kot provides lively musical direction, and Cuddy shows admirable restraint in guiding 9-year-old Kyle Mueller through a charmingly believable performance as Winthrop Paroo that was uncluttered by mugging or an overdose of saccharine.

G.W. Mercier's impressively versatile set is a large open area defined by modules that glide on and off to occupy part of the stage - the Paroo's back porch, the high-school auditorium, a foot bridge near the picnic ground, and especially the railroad car that becomes the setting for the classic opening number, the half-spoken, half-sung "Rock Island." The fluidity of Mercier's design, along with Thomas Munn's precise lighting, helps to keep the show moving forward.

"The Music Man"

Through June 5

Geva Theater Center, 75 Woodbury Blvd.

$28-$65 | 232-4382, gevatheatre.org