It is sometimes amazing to see what directors who have made a successful movie can get away with. One hit, and studios are willing to hand these people a fortune for their dream projects. Heaven’s Gate comes to mind as one archetypal example, but there are many other misfires from award-winning filmmakers. A few years ago director Michael Gracey scored a surprise smash with an original musical, The Greatest Showman. And now he has a new musical film about British pop star Robbie Williams — with a CGI monkey in the leading role.

That’s right, a monkey. This fact was kept under wraps before the first Telluride screening of Better Man. But I guess now the ape is out of the bag. Good luck to Paramount, who will release the movie in December.

In the past there have been classic movies with monkeys as central characters — King Kong, of course, and several of the Planet of the Apes movies. But this one is a little different. Our main character is chimp for the entire movie. Williams voices himself and lends his eyes, but what we see is a simian’s face and body (actor Jonno Davies in a motion capture ape suit, then rendered using computer generation).

Of course he also sings, vibrantly. And it must be admitted that the protagonist’s facial expressions are startlingly effective. There are even several emotionally potent scenes involving Robbie’s relationships with his grandmother (the great Alison Steadman) and his unreliable father (an effective Steve Pemberton). Given the craziness of the concept, it is surprising that several of the scenes work as well as they do.

As you might expect from the helmer of The Greatest Showman, several of the musical sequences are exhilarating, even with a monkey at the microphone. Gracey and choreographer Ashley Wallen bring the dance sequences to life in a riot of color and movement. As he demonstrated in Showman, the director has a gift for putting large numbers of bodies in motion and exciting the audience.

The screenplay that Gracey wrote with Simon Gleeson and Oliver Cole is less felicitous. Even with the bizarre central gimmick, the movie invites comparison to two other recent biopics of British pop singers, Bohemian Rhapsody and Rocketman. (Gracey served as executive producer on the latter.) One problem with this movie is that Williams is not nearly as well known as Freddie Mercury or Elton John. And then of course there’s the issue of adjusting to the idea of a monkey singing and dancing.

The film rushes through all the phases of Williams’ life, beginning with his troubled family, then taking him through his years in a boy band until he decided to strike out on his own. His problems with addiction over the years are addressed forthrightly, ending with his days in some kind of Narcotics Anonymous meeting, where he is the only monkey in the room.

About that monkey, one can appreciate that the alternative approaches to telling this story were not without their own challenges. If the filmmakers had tried to use de-aging techniques to allow Williams to play himself, the artifice might have overwhelmed the movie. And finding another actor to portray him might not have satisfied Williams or the audience.

Speaking of the audience, however, there were a couple of dozen walkouts at the screening I attended, which rarely happens at Telluride. The monkey obviously got to them.

The climax is a huge concert scene, impressively mounted, where Robbie wows the crowd and also makes peace with his family. Unfortunately, the song he performs — Frank Sinatra’s maudlin anthem, “My Way,” which happened to be his dad’s favorite song — doesn’t quite seem to warrant the crowd’s adulation. Maybe the song has become a camp classic. Maybe someday this whole movie will be known as a camp classic. For now it’s a wild, energetic head-scratcher.