PARIS - Vladimir Chekasin was a member of the famed Vyacheslav Ganelin Trio, a late 1970s, early '80s formation from which one expert deduced: ''The spirit of jazz is alive and well in the U.S.S.R. Russian jazz will be the jazz of the '90s.'' It didn't quite work out that way. As a matter of fact, it's hard to keep from laughing. The U.S.S.R. is only a memory, and the trio was not even Russian to begin with. The saxophonist Chekasin, the percussionist Vladimir Tarasov and the leader and keyboardist Ganelin were all Lithuanian. In addition, Ganelin was Jewish - they broke up when he immigrated to Israel. The really big news is that jazz was not in fact invented in Odessa by Jelly Roll Menshikov.

''Improvised music is the only art form that cannot be censored,'' said Leo Feigin, a Russian émigré who released bootleg Ganelin tapes as LPs in Britain. ''By definition, improvisation is invented right on the spot at the very moment you hear it. Ganelin's music was totally subversive in the Soviet system.''

It was so subversive that people who did not even like it listened to it. If you were listening to this it meant you did not want to obey them. The trio made explosive, contemporary music in a time and place when and where jazz was more than just a cool product in a market economy.

Now a headliner on his own, Chekasin appears to have weathered the transition in fine fettle. On one of his rare visits to Western Europe, he drove from Vilnius to Paris this month to perform with the French Compagnie Bernard Lubat as part of the Sons d'Hiver festival in the suburb of Vitry.

Lubat was a guest soloist in the monthly ''Chekasin and Guests'' series in Moscow last summer. Lubat likes to take 40 drummers, 10 saxophones and a vocal choir on stage with him. His performances incorporate elements of Edgar Varese, reggae, polka, rap and his Gascogne roots from southwestern France. Just Chekasin's cup of tea.

The Guardian newspaper in London has called Chekasin the ''Jacques Tati of jazz.'' A compact, volatile, enigmatic and brooding figure, he moves like a mime, jerks like a wired puppet, races through chord changes like Cannonball Adderley and can blow on two reed instruments at the same time like Rahsaan Roland Kirk. Sometimes referred to as ''the peasant,'' he plays his guts out. His eyes, often busy avoiding contact with yours, sparkle with private ironies. He avoids the word ''jazz'' as though it were some sort of contagious disease.

In 1980 the Ganelin trio appeared at the Berliner Jazz Days, its first concert in the West. The critic Joachim Berendt wrote in Down Beat: ''Many listeners perceived the music as a cry for freedom. They asked themselves how much suffering you must endure before your rebellious cry assumes such proportions.''

What was called ''new jazz'' in the last decade of the Soviet Union was derived from American ''free jazz'' during the days of black power - explosive music with political overtones in which emotion and symbolism took precedence over tradition and technique. They were both linked to the plastic arts. ''Free jazz'' and abstract expressionism came together in New York in the Five Spot Café on the Bowery, and Vladimir Tarasov performed a solo concert at the Kuntsmuseum in Bern as part of an exhibition called ''Moscow Artists of the '80s.''

Le Monde said that ''many Soviet musicians have found a way to express their 'Slavic spirit.' Improvised music is doing well in the land of Lenin.'' Even though it may have been invented by slaves, it was considered bourgeois propaganda. The Soviet Union never really figured out what to do with it. And the following generation of players does not seem to be able to figure out what to do with itself.

''I do everything the same,'' Chekasin explains. ''But different.'' He is perhaps best known in Western Europe for his sound track to the film ''Taxi Blues.'' In the East he is known for music accompanying low budget theatrical and television films not released in the West, and his music for the stage. Mostly he performs his own compositions, mostly at home and in Russia and the former East Germany. They are theatrical as much as musical, which is expensive, and so he is a stranger to the summer jazz festival circuit.

The critic Efim Barban once wrote about him: ''Reality sometimes appears in his music as a distorted caricature reflection of the fictitious, as a sham. So that what it excludes as fictitious becomes reality.'' Think about it.

He can speak Lithuanian, Russian and German, and he calls his teaching method, involving law-driven communication, ''operative composition.''

''I reveal objective laws in nature,'' he says, ''laws I did not invent, by the way. There is a certain subjective process inside our body that builds up energy. An objective exchange of energy is produced. Certain choices are made. Every act of communication, which could in itself be defined as a structure, starts with emotion. The structure comes from whatever we agree on. If we cannot agree, we must look for another structure. It does not have to be musical. It can be theatrical or literary or a combination.

''We must try to find new ways of communicating,'' Chekasin continues. ''Communication is more important than going back and depending on already known musical styles. In Vilnius the musicians do not say 'I think I'll play bebop today.' My students are trying to organize new blocks.''

BY ''blocks'' Chekasin means operative structures - abstract building blocks in new neighborhoods with dignity, solidarity and originality. Not suppressers like roadblocks, emotional blocks or writer's blocks. The word ''block'' is perhaps unfortunate. His part of the world was once known as the Eastern Bloc. And a blockhouse is not a pretty image. Perhaps it is only an unfortunate translation.

A decade or so ago, readers of a youth-oriented magazine voted Chekasin the most popular Soviet jazz musician. He shrugs it off: ''I no longer play jazz. The Soviet Union no longer exists. Maybe me, I no longer exist too."