The moment when childhood consciousness breaches the surface, revealing a world beyond the one that has been explained to us, is one of life's true knockouts, a transformation that ranks with death and birth itself. Suddenly an ordered universe of family and school, of right and wrong, of safety and danger, is upside down in an instant. Nothing can ever be the same, but the possibilities are suddenly limitless.

In "Almost Famous," Cameron Crowe's excellent new semi-autobiographical film, William Miller, all of thirteen years old, discovers his sister's forbidden stash of records along with a cryptic note promising that the music will set him free. His sister is leaving home in search of America with a long-haired boy in a convertible, as his mother, who has waged a futile battle against rock music and personal freedom, desperately laments her loss of control. Meanwhile, William slips upstairs to leaf wondrously through the LP jackets: Dylan's ''Blonde on Blonde''; "Wheels of Fire,'' by Cream; Jimi Hendrix's "Electric Ladyland"; The White Album, from the Beatles; Neil Young's "After the Goldrush." He tentatively reaches for "Tommy," by The Who, then cautiously lowers the record onto the turntable. His eyes widen like saucers as the instrumental "Sparks'' streams out from a pair of Sears & Roebuck speakers. It is a sound so magical and transcendent to a teen-ager of the early 1970's that any abiding sense of order could only but dissolve in its presence.

Most cultures have their rite of passage ritual, an institutionalised travail wherein children, particularly boys, are tested with adult challenges. Native American boys, for example, were sent into the forest alone to fend for themselves, a solitary odyssey of physical survival that was also expected to spark an inward transformation. OK, so listening to vinyl records in the corner of a cozy suburban room maybe isn't quite the same. But life today has a different sort of an edge, and personal transformation arrives purely by chance.

Like Cameron Crowe's alter ego, William, for many of us in the past generation or two, our first big flash of new consciousness was brought about not by a physical test but by rock'n'roll. For the Beatles as teenagers, the few American records that filtered back to Liverpool on merchant ships provided a soundtrack to all that was raging within. And to the end of his life, John Lennon always insisted that nothing had ever affected him as deeply as the first Elvis and Jerry Lee Lewis records he had heard as a kid. Bob Dylan crouched under the covers in frigid Hibbing, Minn., transfixed by an all-night rhythm'n'blues station from the south. The reception was shaky, but through the static, Muddy Waters and Howlin' Wolf were able to work their transformative magic. Neil Young heard the ringing Stratocaster of Hank B. Marvin, the guitarist in the Shadows, and in an instant his aspiration to attend agricultural college was put forever on hold.

For many of us whose destinies may not have been nearly as far reaching, the change was equally abrupt and profound. The moment of musical transcendence so beautifully captured in "Almost Famous" was eerily familiar to me. Around 1972, I lived in virtually the same room in the same suburban house, with the same mother and the same sister. The very same albums came into my life, and my mind was forever alterered. In the film, William, still a teen-ager, goes on to become a fledgling rock critic who enters an underworld of road musicians, groupies and marijuana haze, as his mother looks on in horror. Wide-eyed and innocent, William takes to his new life with a sense of awe and wonder. But his mentor, the late great rock critic Lester Bangs, played to perfection by the actor Philip Seymour Hoffman, sets the boy straight. Rock'n'roll is dead, he implores, killed off by corporate greed. William's editors at Rolling Stone are ''swill merchants''; the musicians are not his friends, but rather opportunistic and exploitative mercenaries.

I remember that soon after discovering the music as a teenager, I had the unsettling feeling that I had somehow missed the boat, that the real deal had been the Beatles, the Byrds, the Cream, Dylan before his motorcycle accident. The few survivors of the sixties seemed in the early '70's to be intent only on clutching at the brass ring while it was still there for the taking. The Fillmore East had closed and live music was suddenly a circus of dazed teenagers, hypnotized by the mass media and drugs, stuffed into acoustically disastrous hockey arenas by the tens of thousands.

Rock may have appeared to be in its death throes in 1973. But where else were we to go? The music's spirit had indeed been corrupted but its force was unstoppable. It mesmerized a billion new teenagers and branched off in a thousand different directions. Decades rolled by, Carter, Reagan, Clinton, and people with MBA's solidified their grasp on the music business as the music itself lost its all-pervasive grip on the collective unconscious. But still, many of us hung on for the ride, waiting.

Which brings us to "Time Out of Mind.'' Bob Dylan's first masterpiece in 30 years, the album startled critics when it arrived a couple of years ago with its cranky, poetic rants knocking on the edges of old age. Dylan's "heart is in the highlands," as he sings in the album's epic closing song, but meantime the emptiness of modern life confronts him head on. In the song, he wanders the streets of Boston, feeling ever more detached, enters into an elliptical conversation with a waitress in a diner then winds up in a green park surrounded by attractive, energetic young people. ''I'd trade places with any of them,'' he sings with deep longing, ''if I could.''

It is not a voice of wonder, anything but, yet the music throughout the album is infused with the spirit of new discovery. Never before has Dylan's sound so naturally reflected the music of his teenage heroes. Captured perfectly by producer Daniel Lanois, guitars float through the mix in delicate Mississipi Delta patterns reminiscent of Charlie Patton then howl with the fury of Chicago's South Side blues from the 1950's. Pushing 60, Dylan may have been beaten down by decades of lost love and world-weary wanderings, and his voice sounded rougher and sadder than ever. Yet the album somehow managed to transcend its own darkness by reconnecting with that first moment when a teenaged boy in icy Minnesota stumbled onto a southern radio station playing music that might just as well have come from another planet.

William Miller would surely have understood.