REPRISE; The Extraordinary Revival Of Early Music. By Joel Cohen and Herb Snitzer. Little, Brown. 227 pp. $25.

DURING THE '60s, when a fantasy chronicle by the established medievalist J.R.R. Tolkein achieved the status of scripture, albums began appearing mixing traditional folk and Renaissance musical idioms. Guitarist John Renbourn introduced many to the splendors of ancient dances. Judy Collins recorded a work by the brilliant 14th-century composer Francesco Landini on her Wildflowers album. While college campuses were dotted with young men and women playing recorders and dulcimers, even Grace Slick played the recorder on the Jefferson Airplane's Surrealistic Pillow album. And people wrote like this:

"In a world that seems to grow more and more indifferent to human need, a world where destruction seems to outspace creation, early music performers create music for anyone interested in enjoying, hearing and growing from the experience . . . to make our little field of specialized activity reach across boundaries and fill the whole cosmos with the sounds of renewal and rebirth."

People still write like that. In fact, these words, from the introduction to Reprise, were written by performer and conductor Joel Cohen, who (as you may surmise) is from The '60s. The book is half his words and half Herb Snitzer's pictures of the players (literally and figura who have embraced long-dead music and breathed a new life into it.

Like any instant history, Reprise is anecdotal and casual, witty and frustrating. There is satisfaction that lacunae are being filled mingled with the nagging realization that this can't be the whole story.

It isn't, and it's too bad. The sense of lost opportunity isn't diminished by the fact that Joel Cohen is one of the best people in the early music field, musically and intellectually. Why must he qualify his efforts even in a work of modest scope? "There is no way to 'cover' the whole field of endeavor in an exhaustive manner," he writes, "and we haven't even tried." He asserts that the book is "a personal appreciation of some (but not all) of the important musicians . . . and . . . esthetic and human implications of the work we all do. If you are not mentioned by name, you are here anyway in spirit." Writing of this type calls to mind certain things that weren't so good about the '60s generation.

The rebirth of early music frequently rested on rebellious and free-spirited individuals, getting periodic boosts when like- minded groups of thinkers not in bondage to the accepted norm of art embraced them.

By this view, the cultural phenomenon of the rebirth of early music awaited the actual birth of the person to make it possible. He was born in 1858, and his name was Arnold Dolmetsch. In his eight decades, his impact was enormous; not just on the generation of Dame Sybil Thorndike, James Joyce and G.B. Shaw, who all were affected by Dolmetsch concerts, but on the generations whose influence lives today.

Cohen recognizes that Dolmetsch lived to see his work seem, well, hopelessly old-fashioned. Yet he goes on to show that each performer, each group added in some way to a kind of accumulated knowledge of what must remain forever impossible: to sing and play exactly as they did in 1385, or even 1785.

The great teacher Nadia Boulanger gave the movement the figure of an instructor who placed the understanding of Josquin des Pr,es on an equal level with any great composer. In a confusing lapse of synthesis, Cohen notes that "the most illustrious example of Germanic collegium in the New World remains without question the one founded at Yale in 1943 by Paul Hindemith," without alluding to the fact that Hindemith was Boulanger's pupil. In fact Cohen himself was Boulanger's pupil, yet he underestimates the enormous importance she had in the revival of early music.

As the movement moved forward in musical chronology, and early music types began to tell the big boys in the concert halls that they've been playing Bach wrong all these years, new sparks began to fly. Now generally accepted, using gambas instead of cellos and holding your bow a funny way was and is the hottest issue in this rebirth: "the challenge to established ways of performing late baroque and pre-classical music was by far the most controversial part of the whole early music movement."

Which leads finally to that unanswerable question: is it authentic? We can never have "just one scratchy 78-rpm disk from the sixteenth century of Giulio Caccini's singing," or "just one battered cylinder recording of the twelfth-century troubadour Marcabru declaiming his poems." It isn't to be. From incomplete and unduplicated manuscripts, sometimes from the notational equivalent of chicken scratches, we must intuit the art of an age. Cohen reminds us of the early 1950s, when white jazzmen tried to make an authentic revival of the New Orleans jazz of the 1920s. Even with the old 78s at their disposal, even with some of the living practitioners to copy, the attempt was completely inadequate. If we can't go back three decades, how could we ever hope to go back three centuries?

THE ANSWER IS simple: a revival is not a return. All the scholarship "must be re- imagined by the interpretive artist if the dead work he is charged with resuscitating is to start breathing again." In by far the most important and vital section of the book, Cohen asks, "Do we strive above all for objective knowledge about the music we play, or do we seek to create its inner experience? Who's the god of early music -- is he Apollo or is he Dionysus?" Even though he observes with no little regret that "the ducimer-strumming flower children have been overtaken by a newer generation of trained professionals," it is clear where his sympathies lie. It's possible to be polished, but the soulless hyperacademic approach robs us of any perception of art behind the notes. "Bach was not the operator of some cosmic sewing machine," Cohen reminds us in his impassioned defense of Gustav Leonhardt, "but the author of some of the most expressive and emotion-laden music known to man."

It is a beautifully realized argument that would have been strengthened had the authors decided to make the project less centered on the Boston early music scene. Still, the case made by Joel Cohen for early music is potent. He asks us to embrace something besides "the Mozart- to-Debussy sliver of the past that had already been enshrined by our cultural institutions." When we stagnate, when we are complacent, we die.

"We need the music of our ancestors," Joel Cohen argues. "We need its calm and its passion, its sensuality and its grace. We need the opportunity this music affords us to come face to face with remote yet vitally important parts of our own selves." This is the answer to the question he poses at the end of the book: does the past have a future? As long as people have the commitment of the faces we see in Reprise, or care as much as Joel Cohen, it surely will.