DISPATCHES, adapted, composed and directed by Elizabeth Swados. From the book by Michael Herr. Scenery by Patricia Woodbridge; costumes by Hillary Rosenfeld; lighting by Jennifer Tipton; sound by John K. Chester. Presented by the New York Shakespeare Festival and Joseph Papp. At the Public Theater/Cabaret, 425 Lafayette St., New York City.

Throughout Elizabeth Swados' "rock-war musical," little green words flash past on a ticker tape screen mounted conspicuously in the rafters. They are words, like those sung and spoken below, from Michael Herr's "Dispatches," widely hailed as the best single written record of America's stint in Vietnam.

This visual commentary is a device scarcely calculated to inspire confidence in Swados' confidence in what she was wrought onstage. Is she afraid that her audience's attention may not be fully engaged by the performance itself? If so, her instincts are, this once, right on the money.

"Dispatches," which opened this week at the Public Theater/Cabaret, belongs to the "skimming the cream" school of adaptations. Swados, the writer, composer and director, has pulled a series of powerful anecdotes and impressions from the book, and smothered them in her characteristically furious music and frenzied staging.

Like "Runaways," Swados' stirring musical anthology of nomadic teenage life, "Dispatches" is performed by an ensemble of young actors and singers in multiple roles, deployed across an open stage surrounded by scaffolding. There is no story, just a string of songs and statements.

Swados has said she was out to capture the "emotional essence" of Herr's book. But the book itself was out to capture the emotional essence of the war, and it is hard to do a distillation of a distillation. What has, unfortunately, evaporated in the process is all sense of the war as a frightening business-a war-rather than just a cultural experience.

Herr himself may have provided the excuse for this slightly mad exercise with his observation that when the war was over, "I couldn't tell the Vietnam veterans from the rock and roll veterans." This is not the same, however, as saying that the experiences themselves were indistinguishable, the impression left by Swado's work.

Besides the gunfire that rang throught the book, the other key element largely lost in the shuffle is the raunchy, arch, blitzed-out dialogue that Herr, alone among journalists, had the sense to write down. Swados has used tiny bits and pieces of it, but basically she seems more interested in songs than scenes. ("Runaways," by contrast, rested its songs squarely on the shoulders of a substantial text, derived from interviews with real runaways.)

The songs, on which Swados has chosen to have the show stand or fall, pit her numbing music against Herr's subtle, complicated, prosaic words (as prose, they may sound poetic, but as lyrics they sound an awful lot like prose)-and it is no contest. The words might as well raise the white flag after the first Richter-scale-shattering note.

A low-keyed Herr anecdote about a British publisher seeking a book to "take the glamour out of war" has, for instance, been turned into an inanely intense song with that phrase as its title. And the instances in which Swados has seized on a short and simple theme and invested it with a strong, complementary melody are precious few.

The strongest feature of "Dispatches" is the cast, heavily weighted with actors who can sing and singers who can act. Otherwise, this is a marriage of rock music and print journalism made unmistakably in Greenwich Village rather than heaven.