Fiorello!

He was arguably New York City's greatest mayor: Having served Gotham during the Great Depression and World War II, he is now namesake to a high school for performing arts, a community college, and a marginally functional airport. It's only fitting that Mayor Fiorello H. LaGuardia should have his own Broadway musical, and in 1959 he got one, courtesy of Jerry Bock and Sheldon Harnick (Fiddler on the Roof, She Loves Me). There are hints of those later, greater works in this conservative yet sturdy mounting of Fiorello! from the Massachusetts-based Berkshire Theatre Group, which is now late-summering at the East 13th Street Theatre. With a youthful, fresh-faced cast and no-frills staging by Bob Moss (founder of Playwrights Horizons), it feels like good summer stock.

The book (by Jerome Weidman and original director George Abbott) tells the story of LaGuardia (Austin Scott Lombardi), a pugnacious reform Republican in the mold of Teddy Roosevelt. After securing from party boss Ben Marino (Rylan Morsbach) the nomination to run for a safe Democratic congressional seat, he wins a surprise upset in 1916. In Washington he advocates for war with Germany and enlists in the army as a fighter pilot. He returns home after the war and marries Thea (Rebecca Brudner), an Italian immigrant and campaigner for workers' rights, much to the disappointment of his secretary, Marie (Katie Birenboim), who harbors a secret love for him. LaGuardia wants to be mayor, but he first has to overcome the corrupt Tammany Hall machine that wants him dead.

Gleefully singing in Italian and Yiddish about Tammany tyranny, the baby-faced Lombardi exudes a manic energy that feels right for LaGuardia. It's a trait shared by every successful New York City mayor since (and perhaps the reason why hizzoner never graduates to higher office). Every line is delivered with the force of an aggressive motivational speaker. Lombardi's Fiorello also exhibits a vulnerable side that the actor wisely keeps in check, as any tenacious politician would. So what if he appears about two decades too young for his role? Lombardi more than compensates by fully capturing the spirit of LaGuardia.

Truly, everyone in the cast is young and talented. Brudner's glittering soprano brings yesteryear sheen to the dreamy waltz "Till Tomorrow" and the second-act opener, "When Did I Fall in Love?" The rubber-faced Morsbach is hilarious as Ben, delivering every line with a Jimmy Stewart growl. Chelsea Cree Groen and Dan Cassin are also very funny as Marie's friend Dora and her doltish cop beau, Floyd.

Moss directs the show with Shakespearean fluidity, allowing one scene to seamlessly flow into the next. This is aided by Carl Sprague's nimble set, which features a few key furniture pieces on casters. Bafflingly, Sprague also litters the stage with cardboard cutouts of iconic Manhattan skyscrapers (several of which were not built at the time of the play's events). They don't do much for the staging other than providing an obstacle for the fleeing performers to crash into, like tap-dancing Godzillas.

Michael Callahan's choreography adds little grace to the proceedings. True, the showgirls dazzle with flashy Charlestons and flashier smiles in the number "Gentleman Jimmy." Unfortunately, the movement feels forced on the guy numbers "Politics and Poker" and "Little Tin Box."

Music director Evan Zavada competently leads a reduced orchestra of just two other musicians. While the underscoring occasionally feels thin, the vocals never do. The choral harmony on "Till Tomorrow" is especially impressive.

David Murin's costumes also offer a bit of excess in an otherwise spartan production: Everything is convincingly early 20th century, with thin silhouettes for the ladies and a plethora of hats for the gents. LaGuardia's simple black suit with cowboy hat and string tie makes him look like a sheriff from the old west, riding in on his horse to clean up this town.

If you're in the mood for a good old-fashioned (literally flag-waving) American musical, this is your ticket. Yes, parts of the show come off as passé (especially the number "Marie's Law," which subtly suggests why women shouldn't be allowed to draft legislation), but it's hard not to be charmed by Bock and Harnick's hummable melodies, delivered by an enthusiastic cast. You'll be singing the numbers all the way home.