GEORGE RUSSELL thinks the traditional big band jazz approach has become reactionary.

Sam Rivers rarely uses the big band sound in the customary way, because he says it's overworked.

Gil Evans uses synthesizers instead of the standard set-up of trumpets, trombones, saxophones and rhythm section.

And a young performer such as 23-year-old David Murray is intrigued by the idea of making new sounds with a large jazz ensemble.

It may not sound so at first, but what these musicians have in common is enthusiasm for the big band concept. They want to usher the jazz orchestra into the 1970s, however, and use today's jangling harmonies and zig-zag rhythms.

All except Murray have been working on revolutionizing big bands for at least two decades (Russell and Evans for more than three decades). But they've made slow progress in gaining audience acceptance.

Most people would still rather hear Count Basie's creamy smooth saxophone section singing out "April in Paris" than Russell's band wrestling with the complicated serial qualities of "Living Time."

Nevertheless, the urge to change is strong, says Russell.

"Big bands have been conservative to the point where they've become reactionary, with a few minor adventures into using various time signatures, which in a sense worked out to be essentially mechanical innovations and not truly lasting," he says.

Rivers, a saxophonist who alternates between leading large and small ensembles, says, "The traditional big band style is easy to imitate. That's why so many people play it. You essentially have saxophone riffs that are written down, with some trumpet and trombone punctuations and some solos in between."

Both are referring to the musical style that began with Fletcher Henderson in the 1920s and has flourished like a blue-chip stock since. The style probably reached its high point in the Basie orchestra.

It's also heard in the bands of Woody Herman, Buddy Rich, Maynard Ferguson, Thad Jones-Mel Lewis. They all have a variation or two in instrumentation and have felt the ubiquitous influence of pop music - repetitive rhythms, minimal melodic decoration and electric instruments.

Basically, however, the old big band style puts heavy emphasis on the saxophone section stating the melody in steamroller fashion, accented by crisp or blaring counterstatements from the brass section.

An alternate big band approach came from Duke Ellington, whose compositions were not tunes or sketches but orchestral entities characterized by a broad variety of tone colors, taxtures and tempos and writen for a specific group of musicians - his ensemble.

In his path have followed Charles Mingus, Tadd Dameron, Russell, Rivers, Evans and, to a lesser extent, Sun Ra.

All have created music that skillfully-integrates improvisation with composition.They want the jazz orchestra to evoke impressions of a smog-bound metropolis as well as bright, bubbly youth.

Russell, 55, is currently leading a band that is investigating new rhythmic possibilities. The composer says that in the early '60s he became interested in how rhythm behaved, not simply whether it was in a 2/4 or 17/15 time signature.

"I became convinced that there was a means of scording that would free the musicians from written notes and yet preserve whatever kind of structure I was building," Russell says.

In a performance, he might hold up a cue card for one rhythm, then another to signal that the structure should change. Musicians are free within what Russell calls a "cycle" to interpret as they wish.

"Sometimes I'll direct a cycle. I might have a slow section in cycle and speed it on to a rapid section and different sounds. But the musican isn't held to any bar-line deadlines particularly.

"Sometimes there will be several cycles going on. Maybe a card will say C3. One layer has its function, another layer has its function. It introduces freedom with control. It's a higher level of collective improvisation. The composer doesn't lose his grip on the composition."

Saxophonist Rivers, 47, writes compositions marked by dense harmonic clusters and towering unison melodic figures.

"My harmories are very free," he says. "So is structure. Content is more important than structure. Some pieces I write without notes (he'll ask musicians to improvise in a certain key). Others I'll do with complete scores without improvisation. And in others I'll have a mixture of improvisation and written material."

Many of Rivers' pieces throb with the energy of a giant swarm of bees, moving ahead as one force but containing distinguishable individual voices.

In describing his composition, "Exultation," he partly explains his approach: "I composed without the aid of the piano, disregarding traditional modulations and thinking more in sounds, rhythms, colors, clusters, images, superimposed rhythms and unrelated melodies. Each instrument was thought of and written for as a solo part."

Evans, who's moved away from a glistening impressionism reminiscent of Debussy and Ravel to electronic sounds, said in Down Beat: "I don't like to make public predictions, buy I foresee an all-electric orchestra not too far off. It would have three or four synthesizers, because there are different kinds now: one for strings, one for drums, etc."

Evans, 66, said he was eager to go electronic because of the auditory possibilities that would open up in composition and instrumentation.

After leading his first big band effort, saxophonist David Murray, who's excited the jazz avant-garde recently with his rich tone and darting melodies, was ecstatic. "I want to apply some of the small group concepts like collective improvisation to the big band," he said. "We combined written music with improvisation, all in extended forms. And we were able to change the written music through certain directions from Butch Morris, our conductor. That kind of conducting can make the music spontaneous."

The enthusiasm of these musicians is infectious - but it infects mostly hardcore jazz fans. Most people still prefer to hear the familiar strains of Count Basie's "Li'l Darlin'" or Maynard Ferguson's "Conquistador."

None of the experimentalists leads a band on a permanent basis. Russell, whose band has been playing Monday nights at the Village Vanguard in New York, declares: "The musical economical outlook is promising because there are always people who want to hear the mass of sound that a big band can produce."

Rivers believes younger audiences are more sophisticated than their parents and accept the "new music" more readily. "But I recognize that most people want the traditional approach," he acknowledges.

So for the time being the bands playing new jazz will be hard to find. But their influence will be felt, even among the traditionalists, such as Woody Herman or Thad Jones-Mel Lewis, who occasionally dilute techniques they borrow from the experimenters.

Where does this leave restless searchers like Russell?

"The big band has been a hard instrument to deal with in making an innovative tool," he says, smiling weakly. "And there haven't been many people who've been successful at it. But the situation for change is really right - at least esthetically. You might say the need for change is very present."