Last week at a rehearsal, a page-turner for pianist Keith Jarrett gave him the right reaction to his new composition, "Sacred Ground."

"She didn't know anything about this piece," Jarrett recalls, "but she said it made her want to move out of New York. When I heard that, I said to myself, 'Well, something's working.' "

"Sacred Ground" is music designed to make people dissatisfied with Manhattan, where it was introduced last weekend. Or perhaps Washington, where it will have its local premiere at the Kennedy Center tonight, with Jarrett at the keyboard.

"The piece is about home," Jarrett says, "if we can call our home a sacred ground. The island of Manhattan is not sacred ground. The piece is meant to take you there -- take you home -- for a while. Words can never take you home, but music can."

The music was commissioned by the Chamber Music Society of Lincoln Center, which will join Jarrett in the Washington premiere. Although the work is experimental in a sense, Jarrett says it is "as accessible as a good mattress."

"Sacred Ground" implicitly questions current attitudes about all kinds of established realities -- including cities, music (classical or rock) and property ownership. Inspired by the traditional life and music of American Indians, it tries to evoke or embody their sense of a "sacred responsibility for the planet, their love for it," Jarrett says. In a nutshell, he sums up the difference between that attitude and the attitude of mainstream American society: "They [the Indians] don't understand possession; they like to inhabit their land, but they're not interested in owning it."

"Sacred Ground," he hopes, will be music for people to inhabit, not to possess. "What I hope to do with this piece is stop the separation that so often exists between music and the listener," Jarrett says. "I think our western society has grown to such a point that we don't have any contact with where our music comes from; it doesn't connect with a home. By this, I don't mean merely one spot of ground but something bigger -- North America, perhaps, or the earth."

He polishes off contemporary rock in one sentence: "Rock from London sounds similar to rock from the Midwest; that's media, not sacred ground." Classical music takes a little longer, but he invokes the same principle: People -- performers and audiences -- want to possess pieces of classical music, not inhabit them. That makes them like museum pieces, inanimate objects, unable to change or grow.

Pushed a little, Jarrett will reluctantly admit that he considers music something like prayer: "A medium to conduct a force that comes from somewhere else and lives everywhere. I am trying to show that a modern piece of music can be like this. People have to come to terms with that. People hear this piece and . . . all it does is touch them. It's a very warm and tangible piece. There's not much you can do. You walk down a street and a stranger hugs you and there's not much you can do. It's a mystery, but a mystery you wish would happen more often."

In Jarrett's view, music should be a living thing -- spontaneous, responsive to a particular moment and capable of further development, not fixed and unchangeable. That was the kind of music Jarrett used to produce in his long, wide-ranging and often ecstatic keyboard improvisations, which he gave up in 1983 when he formed a trio with Jack De Johnette on drums and Gary Peacock on bass.

"Sacred Ground," written for flute, clarinet, cello and piano, is not Jarrett's first venture into classical music, which he has been cultivating rather intensively in the last few years, both as a composer and as a performer. Since 1982 he has made solo and concerto appearances in dozens of cities ranging from Stockholm and Toronto to New York and San Francisco, playing music of composers such as Bach, Mozart and Handel, Barto'k and Stravinsky. In October in Carnegie Hall, he gave the world premiere of a concerto composed for him by Lou Harrison.

Jarrett first began composing classical music with himself in mind as soloist (his rhapsodic concerto "The Celestial Harp," for example), but recently he has been writing a lot for instruments that he does not play: an adagio for oboe and strings, an elegy for violin and strings, and a sonata for unaccompanied violin. Without abandoning jazz, he has found a niche for himself in classical music, bringing over the element of improvisation from his jazz experience. "Sacred Ground" has improvised sections "sort of coming out of the written parts," he says.

He believes the balance between written and improvised music must be handled with care: "In this piece, I think the result is one that couldn't have been attained without writing the piece; when you have four people, unless they're on an incredible wavelength, it wouldn't work very well without written parts. But I think that playing written notes is not making music; there is writing music and there is making music. The ideal player would be one who has made so much music that whenever he does written music, he can't help making it."