It’s a Wednesday afternoon, and while the rest of Las Vegas works in cubicles and cashier cages, Nevada Ballet Theatre’s company dancers are stretching, leaping and moving to the strains of composer Michael Torke’s “December.”

Choreographer Matthew Neenan watches, his tongue stuck out in concentration, then suggests a slight tweak. “A little port de bras,” he says, displaying his vision for the move with his own arms. They respond in kind, their bodies lifting in bursts of polished brilliance. Then Neenan stops the music, tries a different variation and has them do it again. It’s hard to say whether it’s more riveting to watch the dancers or the choreographers in this intimate, creative conversation.

This is, of course, no ordinary rehearsal. It’s the birthing process for the world premiere of a new ballet that debuts May 5 as part of NBT’s 46th season finale, Ballet & Broadway. The program will be accompanied by a full orchestra with members of the Las Vegas Philharmonic. Other acts include “Carousel (A Dance),” inspired by the Rodgers & Hammerstein musical Carousel; Tarantella, choreographed by George Balanchine; and “Slaughter on Tenth Avenue,” from the Rodgers & Hart musical comedy On Your Toes.

Neenan’s new dance is designed for nine performers, but twice many that fill the room. NBT Artistic Director Roy Kaiser explains that because this is a brand new ballet, it’s being double cast. That means two or three people will learn each role.

“It’s very important to create new work,” Kaiser says, explaining one of his priorities for the dance company. “Without that ongoing effort to create something new, the art form stops being relevant.” He adds that it also allows the dancers to be part of the creative process, which helps them develop as artists. But most importantly, he says, “It helps create a unique identity for this company. Ten years from now, what will make NBT stand out will be mostly work created here that’s unique to this company.” He hopes that will allow the company to perform more outside Las Vegas.

“The dancers are really talented; they’re smart,” Neenan says about his new interactions with NBT. As a choreographer-in-residence at Pennsylvania Ballet, Neenan has interacted with dancing greats. He also has limited time in Vegas. “To get it to performance level, they have to learn a lot of material in a short amount of time. But so far, so good.”

It just so happens that Torke, the composer, also lives in Las Vegas. He’s dropped in to watch rehearsals and plans to attend the world premiere.

“It’s all inspired by the music,” says Neenan says, who named his dance “Until December” as a tribute to the music that inspired it. “It’s a piece about humanity and nostalgia. In a way, it could be about a memory.”

Nevada Ballet Theater’s Ballet & Broadway May 5, 7:30 p.m.; May 6, 2 p.m.; $29-$139. Smith Center’s Reynolds Hall, 702-749-2000.