Stewart Wallace is a born storyteller. That might seem obvious for a composer best known for operas such as "Harvey Milk" and "Hopper's Wife," in which real events or people often become points of wacky departure, but even in his more straightforward concert music Wallace finds plenty of stories to tell.

His percussion concerto "Gorilla in a Cage," which Evelyn Glennie and the National Symphony Orchestra first introduced to U.S. audiences in 2000, was inspired by his grandmother's losing fight with cancer. "Book of Five," a concerto for the British amplified ensemble Icebreaker, was Wallace's personal response to the destruction of the World Trade Center, which happened within days of the birth of his son.

So when NSO Music Director Leonard Slatkin tapped the composer for a new orchestral work as part of the orchestra's John and June Hechinger Commissioning Fund, it was no surprise that he turned inward for inspiration. But if the message wasn't surprising, the medium was: Wallace's "Skvera," which the NSO will premiere tonight at the Kennedy Center and which recounts his visit four years ago to his grandparents' old Ukrainian shtetl, is a concerto for electric guitar.

"Ever since 'Harvey Milk,' I've been trying to get back to my musical roots," says Wallace, a self-taught composer who served as a cantor in his youth and later found an outlet as a keyboardist and vocalist in a rock band. He was trying to reconstruct family memories from before the Russian Revolution. And he enlisted as an active partner guitarist Marc Ribot, a similarly adventurous musician with whom the composer had been looking to collaborate.

"I've followed Marc both with the Lounge Lizards and in his solo shows, and there was definitely some affinity between us," says Wallace. "If you placed several of my works end to end, even with the stylistic differences you could probably tell who wrote them. Marc's the same way. He's a total sponge, but at the end you sense a very distinct aesthetic holding everything together."

Slatkin, for his part, saw an electric guitar concerto on Wallace's initial list of proposals and jumped at the chance immediately. "I was looking for something different to end the season, and with synthesizers and sampling today, the audience is getting used to electronics in the concert hall," he says. "What was strange at first was that the electric guitar didn't seem to be in confluence with the subject matter. As far as I know, his grandparents never heard an electric guitar. But it became clear that this piece was all about looking at roots from a contemporary vantage point."

Much of Wallace's visit to Skvera, which is about two hours south of Kiev by car, is evoked in sound in the concerto. There are musical portraits of the town's cemetery and synagogue, which had long been converted into characterless factories. And Wallace juxtaposes those flowing lyrical passages with sounds that suggest industrial noise. Sampled within his portrait of the synagogue is a recording of the cantor Yossele Rosenblatt, made in 1916, the year before Wallace's grandparents left Skvera.

A similar shake-up of time and place comes in "Blind Woman Hashkiveinu," a movement for solo guitar in which an Old World cantorial prayer that Wallace sang in thanks for an elderly woman's memories becomes, in the words of the composer, "filtered through New World Mississippi swamp blues."

Do audiences really need to know such extensive background?

"There's always been elaborate stories behind my works," Wallace says. "It's just that today I tend to tell people more than I used to. Not that they need to know anything about it to appreciate the music, but people seem to be interested in the stories."

For Slatkin, that connection has less to do with the scenario than it does with the music itself. "It's important in this day and age to get the audience's attention," he says, "and Stewart's music has both an immediacy that gets you on the gut level and a depth that gets you on an emotional level. This piece has places where the guitar is screamingly loud, and others where it's surprisingly subtle. I think people who don't consider the electric guitar a particularly emotional instrument will be surprisingly moved."

The orchestra has already warmed to the composer, he adds, thanks to a mini-residency during which Wallace got to know many of the musicians personally. The composer admits to writing many individual orchestral parts with specific players in mind.

But if Slatkin views Wallace's piece as essentially an "orchestral work with an elaborate obbligato for the soloist," Ribot, the soloist, sees it as a sincere attempt to deal with the electric guitar on its own terms. "This is a challenge most composers shrink from -- and for good reason," Ribot says. "The electric guitar isn't standardized the way orchestral instruments are, which means there are radically different sounds coming from different brands of instruments, pickups and amplifiers -- and that's before you throw in a whole music store's worth of pedals and effects."

It was over time, and many meetings, that Wallace threw himself into what Ribot calls "the semiotics of the guitar," listening to the distortions and reverbs from several of Ribot's earlier recordings, particularly those with John Zorn, and finding ways to notate the guitarist's quirkiest sounds and settings. "Happily, Stewart didn't run away from complexity," the guitarist says. "He also left room to improvise."

The remaining challenge, integrating the sonorities of an electric instrument with an acoustic orchestra, fell squarely on Slatkin, who has already pondered whether to have the guitar sound emanate directly from the soloist or be broadcast into the house. After rehearsing the piece, the conductor decided to pipe the guitar through the Concert Hall's speakers.

Slatkin says he's looking forward to the test. "As a concerto, the guitar part is certainly virtuosic enough," he says. "I'm not sure how many other soloists will ever be able to play it, but I already have no hesitation recommending this piece to other orchestras."

Stewart Wallace's concerto for electric guitar, "Skvera," makes its debut tonight.