Jazz has long been an urban music. The assertive horns and surprising changes have reflected the hurry-up pace and ricocheting energies of big-city life. Jazz's tones and rhythms have been inspired by the atmosphere of fire escapes, crosstown buses, factory whistles and basement bars. Jazz musicians have tended to live in cities, played in cities and written music about cities.

It's surprising, therefore, to realize that a powerful jazz movement has emerged over the past decade that is not only non-urban, but positively pastoral. This pastoral jazz is rooted in the Charles Lloyd Quartet, the Paul Winter Consort and the Gary Burton Quartet. It is led today by Keith Jarrett, Oregon, John Abercrombie, Jack DeJohnette, Toshiko Akiyoshi, Steve Kuhn and Kenny Wheeler.

In contrast to the tension-0and-release approach of urban jazz, these musicians develop their pieces organically. The harmonies occur more from confluence than conflict; the rhythms are more fluid than forced; the melodies more sensual than sexual.

Rather than forcing their energy through a song like a taxi careening through traffic, they allow the energy to find its own way. The tone of their music reflects the forests, fields, mists and clouds that often illustrate their record jackets.

Yet the music is still jazz. It is essentially improvised music, arising from the gut feelings of the performers rather than from some preconceived plan. Most of these artists have backgrounds in traditional jazz,, and the way they substitute chords, build harmonies and shift times signatures betrays that background. Unlike carefully notated classical pastoral music, the improvisation of pastoral jazz allows the moment to impose order on the music rather than the other way around.

Almost all these artists record for the German-based ECM label. The label's distinctive sound is created by owner Manfred Eicher, who produces almost all the releases. Eicher distills the recorded music to an austere purity. Each sound has a crystal clarity without any fuzzy edges -- a sound that is as well-suited to cool pastoral jazz as it is unsuited for hot urban jazz.

Keith Jarrett -- undoubtedly the movement's most popular figure -- has released three albums this year. Two are disappointing examples of his tendency to pretentiousness.

"The Celestial Hawk" (ECM-1-1175) features Jarrett's piano backed by the Syracuse Symphony at Carnegie Hall. Jarrett's 40-minute symphony sounds overly stiff and contrived; the orchestral strings are a cloying cliche. "Sacred Hymns of G. I. Gurdjieff" (ECM-1-1174) is a solo piano recital of 15 musical meditations by the Turkish mystic. It is religious music for bowed heads in shadowy churches; it's far too solemn for secular listening.

Both these records follow careful notation and lack the spark of Jarrett's improvising. Much better is Jarrett's double live set, "Nude Ants" (ECM-2-1171). Joining the Pennsylvanian Jarrett are Norwegian saxophonist Jan Garbarek, Norwegian drummer Jon Christensen and Swedish bassist Palle Danielsson. The three Scandanavians are so fluid and lyrical that they keep Jarrett's notorious ego in check and make him work hard.

"Sunshine Song" begins with soft, tentative explorations by Jarrett and Garbarek which slowly grow and gain momentum. As the piece warms up, the quiet spaces recede as if evaporating. The same unfurling organic development occurs on "Oasis" and "Processional," which each take up an entire side. On "Nude Ants" (a pun on "New Dance"), Christensen's cymbals and Garbarek's sax create a frenetic rush against the undertow of Danielsson's bass plucks and Jarrett's cascades.

Jan Garbarek has released "Aftenland" (ECM-1-1169), a duet album with classical organist Kjell Johnsen. With no rhythm section, Garbarek's reeds and Johnen's pipe organ blow billowing clouds of sound that expand and evaporate only to be replaced by new plumes. The result is dreamily absorbing if you can do without any beat whatsoever.

One of the many aspects of pianist Chick Corea's career is pastoral jazz. He returns to the form on "In Concert, Zurich, October 28, 1979" (ECM-2-1182), a double live album of duets with vibraharpist Gary Burton. The delicate sound of the vibes forces Corea to play his acoustic piano more lightly and subtly than usual.

Both Burton and Corea leave quiet, pauses where their shimmering phrases can reverberate into silence. Except for three Steve Swallow tunes, all the compositions are Corea's. Corea's pensive restraint is so different from his electric keyboard extravaganzas, it's hard to believe it's the same person. He and Burton are so closely attuned, you can sense how hard they're listening to each other.