The Best Things Happen While You’re Dancing, insists one of the many lilting numbers that buoy Irving Berlin’s White Christmas.

Just add “and singing” and you have the recipe for this charming new stage version of the classic 1954 movie musical. It’s been gaining popularity in recent years as a fresh holiday alternative at theaters from San Francisco to Boston and now makes its Houston debut in Theater Under The Stars’ joyous, polished and ideally cast rendition.

Naturally, a show that exists to showcase a slew of terrific Berlin songs is at its best in the numbers.

At the holiday season and in tough times, people crave comfort food. In the entertainment world, few things are as comforting as Berlin’s songs. Count Your Blessings is the very soul of the show, epitomizing the essential sweetness of spirit that was part of our popular culture in Berlin’s time but is largely absent today — and I don’t think we’re any the happier for having lost it.

Besides, with several shows already compiled from the Gershwin songbook, it was high time someone did the same favor for Berlin (and his fans). White Christmas fills the bill nicely.

The plot is still slight, much of its comedy forgivably hokey. Former Army buddies Bob Wallace and Phil Davis, a successful song-and-dance act 10 years after World War II, find their revered former commander, Gen. Waverly, operating a near-bankrupt Vermont ski lodge, bedeviled by a snowless December. They contrive to boost business by trying out their new show in his barn, while romancing sister act Betty and Judy Haines, amid the inevitable misunderstandings and complications.

David Ives and Paul Blake’s rewrite of the screenplay sharpens and streamlines considerably, clarifying characters and punching up the lead romance. They’ve made the thin tale at times lightly amusing, at others sweetly sentimental and, overall, an efficient and unobtrusive frame for the numbers.

There the show justifies itself, retaining all the best songs from the movie, dropping only a few minor ones. While a few are handled in neat homage, exactly as in the film, most are repositioned or reassigned to make better dramatic use of them.

The show adds a half-dozen more Berlin gems that enhance it considerably — whether onstage turns such as Let Yourself Go and I Love a Piano or situational songs such as Love and the Weather, Falling Out of Love Can Be Fun and How Deep Is the Ocean.

In script or score, just about everywhere this White Christmas has changed things it has improved them. As a result, it achieves a happy medium that eludes most stage adaptations of movie musicals. While sufficiently faithful to please fans, it boasts enough that is different or new to give the stage version its own distinct identity.

The most crucial virtue of TUTS’ production is that its musical values are impeccable.

As Bob, Michael Gruber wields a smooth, mellow baritone that distinguishes every number. He sings Count Your Blessings, How Deep Is the Ocean, the title song and the rest with a simplicity and sincerity that Berlin would appreciate. He’s a nimble dancer, too, and a personable actor with a credible handle on his role.

Beverly Ward invests his love interest, Betty, with comparable vocal flair, adding a burnished, sultry edge to her ballads. Her torchy rendition of Love, You Didn’t Do Right by Me (one we can all relate to) is spectacular and reason enough to attend.

Just as Gruber and Ward convey the lead couple’s common traits — sensible, career-minded, love-wary — John MacInnis’ Phil and Tari Kelly’s Judy strike the right contrast as the devil-may-care second couple. Both fine singers and agile dancers, MacInnis sometimes adding a playfully goofy squiggle to his moves, they make airborne highlights of The Best Things and I Love a Piano.

As the inn’s meddling housekeeper, here also a showbiz vet, Carol Swarbrick delivers lines with sassy bite and belts a fine Let Me Sing and I’m Happy. Kevin Cooney’s Gen. Waverly is the requisite hard-bitten Army man who’s really a softie. As his 10-year-old granddaughter, initially obsessed with history reports, Mallory Bechtel cutely succumbs to the showbiz bug.

James A. Rocco’s direction recalls the lighthearted spirit and showbiz gloss of the musical’s 1950s heyday. His sprightly choreography builds nicely in such production numbers as Let Yourself Go, Blue Skies and I Love Piano, rousingly danced by the well-drilled ensemble.

Jeff Rizzo leads a tight, spirited orchestral performance.

Anna Louizos’ picturesque settings, Carrie Robbins’ glamorous ’50s costumes and Richard Winkler’s glistening lighting give the show sleek, Broadway-worthy production values.

Be sure to stay for the I’ve Got My Love to Keep Me Warm curtain call, with its “special effect” (guess what) that extends through the entire theater and should delight the kid in everyone.