The essence and development of this music is purely American; the basic elements of jazz are a swinging sound and improvisation," says Soviet pianist Vyacheslav Ganelin. "I understood this from a very early age, even though the first music of this kind I heard was played by Czechs."

The leader of the first officially sponsored jazz group from the U.S.S.R. to tour the United States sits at a round table in the Algonquin Hotel just a few hours before the Ganelin Trio's North American debut at the New York JVC Jazz Festival.

Compact, dark and saucer-eyed, Ganelin, 42, is a classically trained composer from Vilnius, Lithuania. He and his cohorts -- percussionist Vladimir Tarasov and reeds player Vladimir Chekasin -- are surely the most avant-garde Soviet artists of any medium yet to participate in Soviet-American cultural exchanges; their searingly dissonant, frequently theatrical performances resemble a jazz style purveyed by American players in loft concerts and "happenings" as early as the mid-'60s. The trio performs in Washington Saturday at 8:30 p.m. in a free concert at Western Plaza (13th Street and Pennsylvania Avenue NW), in a jam session at 11 p.m. that night at d.c. space and again Sunday at 8 p.m. in Baird Auditorium at the Smithsonian's Museum of Natural History.

"It may be," adds Tarasov, the only one of the trio with more than a handful of English words at his command, "that certain things happen faster in the East and different things develop faster in the West." (Ganelin and Chekasin -- and sometimes Tarasov -- speak through their interpreter and record producer, Leo Feigin.)

Black American innovators, including Ornette Coleman, Cecil Taylor and the Art Ensemble of Chicago, originated the subtly structured, spontaneously elaborated jazz favored by Ganelin, Tarasov and Chekasin. Still, it's taken these exotic foreigners to win the attention of such arbiters of taste as NBC's "Today" show. The day after the Ganelin Trio arrived at Newark International Airport, a bemused Jane Pauley peered from the television screen after three minutes of the trio's abstraction based on "Mack the Knife." In a morning time slot unknown to many jazz aficionados, she announced, "Remember, folks, you heard it here first."

The threesome has been playing together since 1971, and though their current 21-day, 16-city tour is their initial trip to the United States and Canada, they've traveled extensively in western Europe since 1980, booked by the Soviet state agency Gosconcert.

All three live in Vilnius now, though Tarasov, who also performs with symphony orchestras, hails from Arkhangelsk, near Finland; and Chekasin, who teaches music when not performing with one of his several jazz and rock ensembles, is from Sverdlovsk, 1,000 miles east of Moscow. They make no claims that their music is evolutionary -- only that it's valid and lively.

On stage they appear somber and absorbed. They also appear fully equipped: Ganelin, with a portable electronic synthesizer sitting atop a grand piano; Tarasov, with strands of small gongs strung next to his traps kit; and Chekasin, with wood and metal flutes stuffed into the bells of two alto saxophones hung around his neck, and perhaps a violin tucked under his arm.

A moody man who confronts every musical situation with fierce passion, Chekasin was given a violin at age 6. Today, he explains through the interpreter, his "biggest joke is to break a violin on stage."

Such acts may confuse fans of traditional jazz and disturb the expectations of critics. One New York reviewer compared the Ganelin Trio's JVC festival concert unfavorably with Chinese water torture.

But how many rock 'n' roll stars regularly destroy their guitars? Blowing two saxes at a time -- one of Chekasin's favorite devices, along with vocalizing nonsense syllables and strutting like a robot -- has been a strategy since the heyday of Rahsaan Roland Kirk, who also used nose flutes and sirens, and shattered glass.

Ganelin's hands dart from piano to synthesizer keyboard or reach into the piano's well to pluck its wires -- an "extended" technique employed by free jazz and academically rebellious "new music" practitioners since John Cage. Tarasov seldom keeps a steady 4/4 beat, though he deftly maintains the pulse and ties together his colleagues' unpredictable fragments of melody or dense snarls of texture with all-embracing polyrhythms.

Heard at the Moscow International Youth Festival last August in a program that featured the cream of Soviet jazz groups, the Ganelin Trio was more formidable, original and avidly appreciated by the mostly Russian audience than the mediocre Soviet jazz-rock fusion band Allegro, the romantically effusive solo pianist Rayne Ragniap, or the Vaudevillian "jazz -- variety" ensemble that harkened back to Soviet jazz of an earlier era.

In "Red and Hot: The Fate of Jazz in the Soviet Union" (Oxford University Press), the historian, jazz clarinetist and Oberlin College President S. Frederick Starr devotes a chapter to the Duke Ellington and Count Basie of Stalinist Russia -- Alexander Tsfasman and Leonid Utesov. Ganelin and Tarasov heard records by Tsfasman and Utesov from childhood on, but realized (as Feigin translates), "It was light entertainment. Maybe both Tsfasman and Utesov in the very beginning tried to play jazz, but later on they led simple pop dance bands, with slight elements of sentimental improvisation."

The Ganelin Trio, like its American jazz counterparts, insists upon the sincerity of its expression and the seriousness of its purpose.

Leo Feigin is a Leningrad expatriate and radio producer for the British Broadcasting Corp.'s Russian service. He's issued nine albums by the Ganelin Trio on his label, Leo Records, and edited "Russian Jazz: New Identity" (Quartet Books), an anthology of essays concerning the progressive school of musicians active in the Soviet Union in the '70s and '80s.

In New York to speak with the press for the Soviet trio, Feigin explains, "Ganelin says jazz expresses the essence of the human being -- his character, his personality, his individuality -- because jazz is the only music which gives one direct communication with other people. I myself believe that in performance each of these musicians retains his own personality, his own viewpoint. Sometimes it leads them to break the structure that they're playing, sometimes to sustain it."

What does the Ganelin Trio hope to fain from their first encounters with U.S. audiences? Feigin translates Ganelin's response while Chekasin and Tarasov nod approval:

"As any artists who play for an audience without defeating them, who trust the audience with their heart, these musicians say they hope for audiences who will not be wearing blinkers or reject what they offer. They hope for open audiences who come to their concerts with open minds."

Howard Mandel is a New York writer specializing in jazz.