It’s a scene of dizzying chaos in an upstairs rehearsal studio, as a dozen or so Colorado Ballet dancers madly crisscross each other from all directions, men twirling and leaping in solo jetés, women lifted aloft by strong-armed men and rushed forward at full speed, seemingly within an inch or two of other couples moving in opposite directions as a piped-in brass fanfare reaches a furious climax.

Then, the craziness suddenly ends.

Everyone stands in solemn rows and all begin to slowly, elegantly take a few steps in unison, arms beautifully extended as they move toward a distant horizon.

The ballet has ended. Disaster was avoided.

Watching it all approvingly is Urtzi Aranburu, a man who knows every second of this thrilling piece, Jiri Kylian’s Sinfonietta, one of the Czech choreographer’s early masterpieces.

That work, created in 1978, had been danced countless times by Aranburu while a member of Kylian’s Netherlands Dans Theater. Set to the orchestral score by Leoš Janáček, this complex piece will serve as the conclusion of a three-part “Masterworks” program, the finale of Colorado Ballet’s 2022-23 season, opening Friday in the Ellie Caulkins Opera House.

Now retired, Aranburu has served for 10 years as a repetiteur, or ballet teacher, with the Kylian Foundation, traveling the world and staging the fabled 76-year-old dance maker’s works for companies judged capable of presenting his creations.

Surprisingly, he confessed, this is his first go-round teaching the popular Sinfonietta. Last season, Colorado Ballet conquered Kylian’s Petite Mort, so perhaps this year’s entry serves as a reward for a job well done.

Not that this is a walk in the park for the dancers.

After an hour of rehearsal, two dancers talked about Kylian’s challenging choreography, particularly that crazy finale.

“It took us three hours to get it,” Leah McFadden said of their introduction to all that leaping and dashing about. “We started in slow motion. Urtzi gave each of us individual (dance) counts. Still, there were so many near-crashes.”

Jonnathan Ramirez chuckled at the memory of those early run-throughs, but stressed that the choreographer and his faithful repetiteur were not cruel to dancers.

“It’s exhausting at the end, but when you get it right, it feels wonderful — when the music and the movement connect,” he said.

McFadden nodded in agreement, adding, “There’s nothing awkward. It feels natural. It’s challenging, but it’s fun, really. Dancing this work is so energetic.”

While the dancers stretched and warmed their limbs upstairs, Aranburu spoke about the pleasures and perils of setting Sinfonietta on the company: “Everybody works very hard, and it’s gone very smoothly so far. Everyone looks very beautiful.”

As Ramirez noted, Aranburu emphasized the link between the music and the dance.

“The musicality is so important, for them to feel in sync with the music, to have the dancers try and be part of the orchestra,” Aranburu said. 

A crucial element in that connection is the presence of a pit orchestra, which will accompany all three works on the program. Audiences will experience an unexpected thrill when a brass ensemble plays the opening fanfare of the Sinfonietta from inside the hall. For the dancers, however, performing to live music has its dangers, particularly with the Janáček score.

“That fourth movement has to be (played) very, very fast,” Aranburu said. “But not too fast. I’m worried about that.”

After rehearsal, McFadden echoed that concern: “I’m in that fourth movement. It’s either fantastic or it’s horrible, depending on the tempo.”

I assured them both that all will be well, having been familiar with the consistently solid work of company music director Adam Flatt for many years.

Sure, dancing this speedy, high-energy work can be fun for the dancers — once they get the hang of it. But, as Aranburu casually mentioned, it can also be physically risky. Referring to the pas de trois, an intricate trio for two men and a girl late in Kylian’s work, he allowed that, while it isn’t all that difficult to teach, there’s no margin for error. The three dancers hold onto each others’ wrists almost continuously, he explained, but they must change grips at key moments.

“Otherwise,” he said matter-of-factly, “she might separate her shoulder.”

Colorado Ballet will perform George Balanchine’s “Prodigal Son,” Clark Tippet’s “Bruch Violin Concerto” and Jiri Kylian’s “Sinfonietta” April 14-23 at the Ellie Caulkins Opera House, the Denver Performing Arts Complex.