Their carefree laughter quickly quiets down as a rehearsal for the Children's Dance Theatre performance of "Scientia" resumes and the opening futuristic-sounding notes of the second dance, Prism, fill the gym.

Groups of children dance across the makeshift stage with varying intensities, some moving faster than others. They represent different energy levels of colors in the light spectrum. As the energy levels of the dance vary, so does the speed and intensity of the music.

"The score is more electronic-sounding than usual this year, to capture the contemporary, forward-looking essence of the show," said Tristan Moore, the resident musical composer for CDT and co-script writer. "Electronic-sounding samples have always been a comfortable part of my palette, but this show's science theme has allowed me to bring them further into the foreground."

"Scientia," Latin for knowledge, is the theme for this year's performance and is a break from past performances, which had more fairy-tale motifs to them, Moore said.

While he has been collaborating musically with CDT for the past seven years, Moore has grown up with the company, dancing as a child and returning after finishing college in 2001.

"It's so different for CDT . . . this time we are really taking on contemporary issues with relevance to people living in the 21st century," he said. "It's about the sense of wonder that can be rekindled by science's strange discoveries."

The sound of the music for the performance resembles industrial, electronica and new age, perfectly complementing the theme behind the dances. The performance begins with a dance called Galaxies, includes dances about atoms and the immune system, and ends with "A Fine Balance," a dance about the destructive arm of science and technology.

"It shows us where we are right now - on the brink - and it's up to us to care for the Earth, as individuals," said Mary Ann Lee, the artistic director for the company for the past 29 years.

Bill Bryson's book, A Short History of Nearly Everything, which tells the stories behind the scientists who made significant scientific discoveries, helped inspire the performance.

"We got to thinking, 'why don't we do a science theme?' " Lee said. "You can take your inspiration from almost anything . . . It really shows the optimism of science and that we can all embrace science."

A word or phrase from Bryson's book, such as Dangerous Beauty, motivated some of the choreographers for their dances. Others used a field of study, such as genetics, as a springboard to create the dances.

"I watch as much as I can of the choreography in progress, videotaping and notating and talking with the choreographers about their intentions," Moore said.

"Then I organize the palette of sounds into multilayered sequences on my computer and Roland workstation, arranging synth and sampled instruments into musical sections intended to match the visual action."

Another challenge for Moore and his sister, Sadie, who co-authored the script, was to develop a thematic unity for the show.

"We were then asked to take these seemingly disconnected elements [chosen by the choreographers] and bring them together into a semblance of a coherent plot," he said.

To unify the scientific themes, the siblings added a little extra spice to the performance.

"We wanted to do something different from the other years . . . and after exploring other possible avenues, Tristan and I decided to give it a more theatrical science fiction twist," said Sadie, a University of Utah English major.

The resulting script includes more acting than in past years and uses time travel to explain the scientific discoveries.

"Because I was involved in the script writing, I had a pretty clear idea of what types of sounds and instrumentation might be appropriate. This show depicts both the utopian and dystopian aspects of science," Moore said.

He gave examples of science's ability to cure diseases and create new and helpful inventions but also permits creation of atomic warfare and environmental destruction.

"I wanted that dichotomy to come across in the score," he said. "So I started by juxtaposing human-manufactured sounds against more organic, natural sounds. And I went from there."

Graham Colgan, an 8-year-old dancer, said he's learned a lot of science for this year's show: "A prism is a shape of a triangle extended, and it refracts light and shows colors that are already there."

Look for the colors in the dance, he said.

"I've been in three [performances]," Graham said with a shy smile, "but I think this one will be my favorite, because the dances involve a lot of people."

Want to see the show?

* "Scientia" plays today at 7:30 p.m. and tomorrow at 2 p.m. at the Capitol Theatre, 50 W. 200 South. Tickets are available by calling 801-355-2787 or by visiting www.arttix.org.