They're on the same wavelength

When choreographer Dana Reitz talks about a work's ''score," she's not referring to the musical accompaniment for one of her dances -- at least not in any traditional sense.

''The dancers are the music," she says by phone from her upstate New York home. Not that they're making sounds; in fact, Reitz doesn't use music. What she means is that each gesture in her work is as precise and refined as a note played by a master musician.

Boston audiences will get to see what that means on Thursday, when Reitz premieres ''Sea Walk" at Summer Stages Dance at Concord Academy. The piece is a trio for Reitz, Sara Rudner, and Christine Uchida, all great dancers with distinguished careers.

All three women are now over 50. For Reitz that's a plus. ''Seasoned" is the term she uses, but it's not a euphemism. She's talking about dancers who don't need to prove themselves by kicking their legs up past their ears, dancers who'd rather dig into the subtleties of a piece.

''These three women helped define the gold standard for what people mean when they talk about great modern dance," says Ella Baff, executive director of the Jacob's Pillow Dance Festival. The three were all members of Twyla Tharp's company for various periods of time, and Baff recalls that ''when they danced with Twyla they moved, thought, reacted, and invented onstage in a way that was totally new. No one had ever seen anything like it. It was fireworks."

Reitz's work is more like a gentle meteor shower. Her score also includes the lighting, which in this case is by Rick Martin. On first seeing the theater at Concord Academy earlier this summer, Martin said, ''Oh my God. This is the anti-space," Reitz recalls. But they were determined to make it work. That resulted in illuminating the space over the stage and the audience by shooting light out from the proscenium in ''ripples like soft waves," Reitz says. ''This kind of lighting has texture," Uchida adds by phone. ''It's not just there to make you look good."

''Sea Walk" is an hour long without intermission, and its success will depend greatly on how attuned the three women become to one another during their rehearsal period. They're more or less cloistered at Reitz's rural home, where she lives because she teaches at nearby Bennington College.

It helps, of course, that they already knew one another, through Tharp and other connections in the small, intense world of American modern dance. In the early 1990s, Rudner and Reitz worked together on Reitz's ''Necessary Weather," which, when danced by Rudner, became acknowledged as a masterpiece. ''Dana's work is the most beautiful and immediate experience I've ever had on a dance stage," says Rudner.

Reitz and Uchida, both part of the downtown New York dance scene of the 1970s and '80s, reconnected by chance in the '90s in the boutique Uchida was running in Manchester, Vt. ''I was in denial about dance," explains Uchida, who had quit dancing. ''Dana coming into the shop was the beginning of my coming back."

Uchida eventually signed on. ''Sea Walk" is her first experience with Reitz's choreography. ''We spend a lot of time talking about movement," she says of Reitz's working method, ''and Dana will make charcoal drawings of gestures. She'll move the drawings around like pieces in a puzzle."

''I develop phrases that are very precise, very detailed, and intimately coordinated with the lighting," Reitz says. But there's also enough leeway for each dancer to perform those phrases differently. She compares this to the way jazz musicians work together, improvising on a theme.

That combination of structure and leeway is enticing to dancers: It's what led Mikhail Baryshnikov to commission a solo from Reitz, ''Unspoken Territory." He performed it all over the world, some 250 times. (In Russia, its intricate lighting design was beyond the capabilities of the Soviet-era equipment, and at one performance, the solution of the stout ladies running the light board was to kneel and pray in front of it.) Such a long run is a modern-dance choreographer's dream: to make a work that has staying power far beyond the usual weekend in a loft space -- end of story, end of dance.

In talking about her choreography, the term Reitz comes back to most often is ''precision." She makes her work sound like a Swiss watch. A reviewer once wrote that an audience member who had to cough during one of Reitz's silent works would feel just awful about the disruption.

Reitz knows, though, that she can't control everything that goes on during a performance, either onstage or in the audience.

''I don't mind coughers," she says with a smile in her voice. ''It's not a problem."

''Sea Walk," choreographed and directed by Dana Reitz, is at Summer Stages Dance, Concord Academy, Concord, Thursday. 978-402-2339, www.summerstagesdance .org.