Early on in freeFall Theatre’s production of “What a Glorious Feeling!” two impressive performers playing Gene Kelly and Stanley Donen start tap dancing wildly inside a small Hollywood rehearsal studio. They’re creating steps that will become a crucial part of the tongue-twisting song “Moses Supposes” in their classic 1952 film “Singin’ in the Rain.”

John T. Wolfe as Kelly and John Michael Lopez as Donen, conjure up a thunderstorm of tapping while stirring a sensation of pure, unadulterated joy at the creative process. They dance in unison and then challenge one another toward ever-more intricate steps. Their minds and feet are in sync as they take one idea and build it to something more. As much as audiences will focus on how much their feet are moving, they can’t miss the smiles on the performers’ faces.

Wolfe and Lopez have several more opportunities to showcase their hoofing skills in both soft shoe, tapping and balletic routines, and each time, they bring the audience along with their propulsive energy and infectious enthusiasm.

But apparently all was not well behind those steps in Jay Berkow’s fictionalized backstage look at the relationship between the two men and the creation of “Singin’ in the Rain.”

They worked frequently together as innovative choreographers and co-directors, though Kelly was always the bigger star because of his on-screen roles. According to Berkow’s play, their relationship was often uneasy and tinged with jealousy, envy, regret and anger, along with deep respect.

In a telephone interview before Saturday’s opening night (I reviewed Friday’s final preview), Berkow said he had attended a discussion years ago in which Donen refused to talk about Kelly. The playwright and director, intrigued by that lack of response, started imagining what might have led to the animosity. He later discovered they had both been married to the same woman, a dancer and assistant named Jeanne Coyne, who may have come between the two creative geniuses.

She was Kelly’s longtime assistant and apparently in love with the married Kelly star. Coyne ended up marrying Donen – one of his five wives – and was later married to Kelly for 13 years until her death in 1973.

“What a Glorious Feeling!” is set entirely in the intimate rehearsal studio designed by Hansen Scenic, which leaves plenty of room for the small cast to try out numbers in development, from “Broadway Melody” to “Good Mornin’,” “You Were Meant For Me” and of course the film’s title song, with the help of accompanist and music director Michael Raabe.

Berkow interweaves the selection of songs and how they are staged and treated with the struggles between Donen and Kelly over Caroline Lynch Desmarais as Coyne, who still has feelings for Donen but can’t deny her long-abiding attraction to Kelly. Desmarais dances with a similar ease, playing a woman who might have been a dance star in her own right.

They’re joined by Laura Gulley as the newbie Debbie Reynolds, who has her own kind of sparkle, even if she struggles to keep up with two masters. She admits to being so nervous about messing up routines that she can’t help messing them up.

Donald O’Connor, the third top-billed star of the film, is not a character in the play. But Berkow does bring in the songwriter and producer Arthur Freed, whose songs are highlighted in the film. Sarasota-based actor Larry Alexander brings a certain charm and nervous energy to the role as Freed tries to keep costs under control amid corporate changes at the studio, Metro-Goldwyn-Mayer.

There are aspects of the story-telling that don’t always make sense – you have to believe that these numbers were at least envisioned long before filming was to begin so that sets and costumes could be made – but director Douglas J. Hall keeps the energy high while putting the focus on the implications and ramifications of that romantic triangle.

The unseen star of the show is the choreographer Chris Shin, who has created several rousing routines performed in a small space that suggest –without copying (or stealing) – what audiences remember from the famous film.

Overall, it results in a delightful couple of hours, and should prove to be a fine warm-up before Asolo Repertory Theatre presents its own stage version of “Singin’ in the Rain” in November.

“What a Glorious Feeling!” by Jay Berkow. Directed by Douglas S. Hall, Reviewed Sept. 18, freeFall Theatre, 6099 Central Ave., St. Petersburg. Tickets are $55. freefalltheatre.com; 727-498-5205