EAST HADDAM, CONN.- At this point we have been burned by many musical adaptations of beloved movies, and reactions have ranged from “Why did they even bother?” to “Dear God, please make it stop.” So it was with some trepidation that I traveled to the Goodspeed Opera House in Connecticut to check out its take on Charles Walters’ “Summer Stock,” from 1950.

The movie’s plot in shorthand: Gene Kelly and Judy Garland put on a show in a barn, and then she sings “Get Happy” at the end. Naturally, that last exhortation pops up in the world-premiere stage version (twice, even) currently running in East Haddam, but it is easy to take to heart: The show may not be perfect, but its craftsmanship, zest and good humor — which are deceivingly hard to achieve without falling into bland cheerleading and forced joy — are perfectly dosed and on target.

The book writer Cheri Steinkellner stuck to the movie’s spirit rather than its letter, though she wisely did not mess with the central conceit: A group of theater kids led by director Joe Ross (Corbin Bleu, last seen on Broadway in the 2019 revival of “Kiss Me, Kate”) find themselves rehearsing a musical on the struggling farm of one Jane Falbury (Danielle Wade).

A notable change is that in director-choreographer Donna Feore’s production, the local businessperson and Jane’s sort-of antagonist, Jasper Wingate, has become the stern Mrs. Wingate (Veanne Cox, in supreme form), who wants to take over our heroine’s land to create “the largest commercial farming operation in the Connecticut River Valley.” The Wingate heir is still an oaf named Orville (Will Roland, from “Be More Chill”), but this time around he has a secret — no, not that one. When Jane must find money to save her farm, Joe suggests using his show for a benefit.

In the movie, Jane’s barn looks to be of an average New England size from the outside, but magically turns out to be capacious enough to accommodate big numbers. In contrast, the Goodspeed building is impressively large when you walk up to it, but the theater nestled within only has about 400 seats and a fairly small stage, lending “Summer Stock” a welcome intimacy and suggesting the gee-whiz enthusiasm the story requires.

Steinkellner and Feore know when to update, when to leave well enough alone, and when to have it both ways. In the reprise of “Get Happy,” for example, the ensemble wears the same black suits and coral shirts as in the movie, though now we also get amusing explanations for how Jane ended up in a fedora and a tuxedo jacket, and how the painted background acquired its pink hue. Hint: The beefed-up character of Jane’s sister (Arianna Rosario) has a hand, or foot, in both.

But what really makes this “Summer Stock” pop is its cast, which appears to be having a blast — another element that is too often missing. Bleu, who got his start portraying a young basketball star in the “High School Musical” franchise, has become a terrific interpreter of golden-age fare. His athleticism and deceptively casual nonchalance allow him to effortlessly lead energetic dance numbers such as “Dig for Your Dinner,” and his voice has matured into a warm baritone that works wonders on “It Had to Be You” (one of the too many songs added to the show). As Jane, Wade can’t quite summon up the same firepower, but they still make a fine couple.

Chewing up the barn with great gusto, Cox, Roland and J. Anthony Crane (playing the hammy, vain thespian Montgomery Leach) leave behind contrails of laughter every time they exit the stage. As Garland sang in another classic “let’s put on a show!” movie, “Girl Crazy”: Who could ask for anything more?

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‘Summer Stock’

Through Aug. 27 at the Goodspeed Opera House, East Haddam, Connecticut; goodspeed.org. Running time: 2 hours 40 minutes.

This article originally appeared in The New York Times.