Jazz has a beat, but does that make it a time zone?

IT is one of today's little ironies that when we're not accusing ourselves of having no sense of history, we're accusing ourselves of nostalgia. Can you have it both ways? To correct this logical flaw, the ``purist'' has been invented. The purist is a person who is passionately knowledgeable about the past -- a true historian to the point of tears. But nostalgia? What nostalgia? It's not his fault if an objective study of his branch of history teaches him that the Golden Age began thus and ended so, and darkness has descended upon the face of the earth ever since.

Film purists, for example, cannot escape the conclusion that the fall from grace occurred with the invention of the sound track.

Jazz purists divide into two groups: the pure purists, who think the art form closed shop when Louis Armstrong corrupted his Hot Five into his Hot Seven; and the fairly pure purists, who allow the Golden Age to extend to World War II, but that's about it. Forget Charlie Parker and Miles and Diz. Everything ended with the Big Bands of the '40s and the little swingers on 52nd Street.

The fairly pure purists of jazz are not exactly carrying the hour, like fundamentalists and neoconservatives in other departments of the '80s. But they're not the tiny minority within a musical minority that they used to be.

A sign of our 4/4 times:

The old jazz record reviews of the English poet Philip Larkin -- a fairly pure purist -- have been reissued under the title ``All What Jazz,'' receiving generally respectful reviews in the American press. Ten years ago, one ventures to guess, his assessments would have been considered cranky and illiberal -- and what does an Englishman know about jazz, anyway?

Other fairly purist indicators:

Reissue projects, like the Time-Life jazz series, can halt themselves at that World War II fairly purist dividing line and not -- you may be sure -- lose money by the decision.

Young musicians, like the accomplished tenor saxophonist Scott Hamilton, are allowed to model themselves after giants of the Golden Age -- in Hamilton's case, Ben Webster -- without having to suffer the sneer: ``Derivative!''

It is sad to see the cheering section fading a bit for what used to be called ``progressive'' jazz. After all, what is jazz in the first place if not an act of musical spontaneity, improvising its own rules?

But the one unqualified blessing of the fairly purist trend is that jazz veterans are now treated as living legends -- under glass, yet. Once, the appetite for The New caused jazz musicians to be discarded as outmoded while still in their 30s. Today, now in their 60s and 70s, they are invited to play at the Smithsonian or at Carnegie Hall, where they are reverently enshrined on videotape, or audio cassettes at the least.

A recent instance is the concert sponsored by the Book-of-the-Month Club, and issued this month as the first album of Book-of-the-Month Records under the title ``Swing Reunion.'' The occasion joined together at New York's Town Hall Benny Carter (alto saxophone), Red Norvo (vibraphone), Teddy Wilson (piano), Freddie Green, Remo Palmier (guitars), George Duvivier (bass), and Louis Bellson (drums).

Everybody here except Bellson goes back to the '30s. Carter and Norvo go back to the '20s. When jazz musicians avoid the early-burnout of a Bix Beiderbecke, a Fats Waller, or a Bud Powell, they can be durable fellows, indeed.

Like other time-defying jazz acts of the '80s -- trumpeters Doc Cheatham and Harry ``Sweets'' Edison, saxophonists Buddy Tate and Illinois Jacquet, and the late blues singer Alberta Hunter, to name just a few -- Carter and Norvo astonish the ear with septuagenarian freshness. It is not simply a matter of two old boys maintaining youthful standards of technique and energy. On tunes like his own ``Evening Star,'' Carter plays sophisticated harmonic intervals that are light-years ahead of his Chocolate Dan dy days. Norvo gives old warhorses like ``How About You?'' a subtlety of phrasing, a control of touch that make the postmodern ear stretch deliciously to catch the nuances.

The point is, these players -- and all the other old (and young) jazz hands growing on their own terms -- function within a state of grace that is more timeless than we think. It is the traditionalists and the modernists and all the other categorists watching from the outside who are trapped in time zones.

To paraphrase Armstrong, if it swings, man, just stamp its visa and let it move along.

A Wednesday and Friday column