PHOTO © UNIVERSAL PICTURES

We are here to listen to Cynthia Erivo sing, and when she does, it’s magnificent. Unfortunately, the rest is frosting — an immaculately constructed yet oddly tasteless confection.

“Wicked,” or “Wicked: Part One” if you’re not a studio executive trying to hide the fact that this is only the first act, has been in the works quite some time. The stage musical of the same name, which premiered in 2003 and earned a trio of Tony Awards, is one of the most successful in Broadway history. The tale of Elphaba, known to us as the Wicked Witch of the West, has dazzled audiences with its soaring songs and revisionist fairy tale. Rumors of a screen adaptation were swirling within a few years of the show’s debut.

Finally arriving more than two decades into the show’s New York run, the result is impressively designed and beautifully rendered. It packs a mostly game cast, led by a transcendent Cynthia Erivo as Elphaba; she does not merely interpret the material, she elevates it.

Her co-star, Ariana Grande, is funny and charming as Glinda — even if she can’t nearly match Erivo’s vocals. (She’s also given more songs, at least in this half, much to the film’s detriment.) Jeff Goldblum amuses as the Wizard of Oz; Peter Dinklage lends an excellent voice performance as Dr. Dillamond, a persecuted, caprine professor.

There are talented people here giving great performances in a richly visualized setting. “Wicked: Part One” has all the ingredients of a lovely film.

It’s just deadly slow.

The sea of technicolor artifice might suffice were it not for the film’s languorous pace. Director Jon M. Chu, who did an infinitely better job handling the adaptation of “In the Heights,” seems determined to move the plot as slowly as possible; his camera placidly drifts around set pieces. He neglects to shape the audience’s experience of the story, instead wandering aimlessly around his own film.

He’s not wholly responsible for the arrested movement, though, as much of the blame should be ascribed to the avaricious decision to split one well-contained story into two films. Desperate to get the audience to buy two tickets instead of one, Universal has taken the story and chopped it off at intermission; the result, in the case of “Wicked: Part One,” is a story that only finds its footing before the credits roll.

To illustrate the absurdity: On Broadway, “Wicked” runs 165 minutes, including a 15-minute intermission. On the screen, the first half of “Wicked” runs 160 minutes. Regrettably, there is no intermission.

In New York, they’ve told Elphaba’s full story in 150 minutes on 8,160 separate occasions (and counting). Universal needed 10 more minutes to tell half of it.

That can only indicate a film that is more interested in making money than in satisfying the audience. That’s a disservice to Erivo and the many talented artisans behind the scenes; there’s plenty of good here, and many genuine moments of entertainment. Unfortunately, those moments have a lot of unnecessary fluff between them. One moment, your spirit will soar; the next, you’ll check your watch.

My Rating: 6/10

“Wicked” is now playing in theaters.