The first thing everyone saw was hair.

The first thing everyone heard was screaming.

On that Sunday night in February, 1964, Ed Sullivan unlocked the gates of inhibition and unleashed The Beatles on an American television audience for the first time, and the pop culture was never the same.

The moment they went into the "Oh yeah, I . . ." lyric of "I Wanna Hold Your Hand" marked the first shot of a social and cultural revolution that was brand the '60s as a decade of rapid, chaotic change. And it was led by these four young men from Liverpool called The Beatles, who, in turn, were led by the wittiest, savviest, most daring among them, John Lennon.

Lennon was the key to the cultural phenomenon that was The Beatles, and the key to Lennon was his rebellious desire always to go beyond the norm, always to push the limits outward. To create a new style, a new ethic. It went far beyond the hair, into the psychedelic era of hallucinogenic drugs, into the contemplative era of transcentental meditation, into the passive and ultimately active resistance of the anti-war movement during the Vietnam era.

"A pop explosion," wrote Grief Marcus, as he tried to explain the impact of The Beatles on the '60s, "is an irresistible cultural upheaval that cuts cross lines of class and race . . . and, most crucially, divides society itself by age."

And always at the point, there was Lennon. Lennon with the smoked glasses. Lennon with the sage's beard. Lennon with the puns and pornographic drawings. Lennon with the curious Japanese woman. Lennon in the bed and in the bathtub, singing for peace and wondering why everyone else wasn't naked and singing, too. And finally, in the late '70s, Lennon, the reclusive househusband who withdrew from the music scene completely.

"I knew they were pointing the direction where the music had to go," Bob Dylan said of hearing The Beatles for the first time. "It seemed to me that a definite line was being drawn. This was something that never happened before."

A definite line.

Which side are you on?

The parents tried to set limits.

The kids wanted it all.

And The Beatles said, take it.

The Beatles style took the postwar baby boom and molded it, shaped it and defined it to the beat of their records. With every new album, they moved it along. From "Meet the Beatles" to "Rubber Soul," to "Sgt. Pepper," to "Revolver," to "Abbey Road." Such was their hold on the youth of the '60s that virtually everything they said or did immediately become gospel.

There was one key phrase, from "A Day in the Life."

It was their message and their fondest wish:

"I'd love to turn you on."

Hair. Gimme it down to there, shoulder length and longer. Beatle wigs. The Beatle cut. Everybody stopped going to barbers.

Drugs. "Lucy in the Sky With Diamonds." Oh, yeah, the fans got it. LSD. The Beatles not only said they smoked pot, which made it immediately okay with their followers, but said they dropped acid. Said it changed their lives. Acid swept the college campuses and high schools of this country like some kind of locust plague.

The Stoned Generation tuned in turned on and dropped out of normal 9-to-5 life sit in front of stereo sets and groove on The Beatles. They studied the lyrics for subliminal drug messages. Head shops, catering to the drug paraphernalia business, flourished. Even Johnny Carson, the purveyor of the pop culture to the middle-aged masses, started doing drug jokes.

Meditation. It may have been George Harrison who found it first among The Beatles, but Lennon and Paul McCartney gave it the certification it required to seep down into the followers. Sitar sounds found their way into the albums. The Beatles went to India to study with Maharishi Mahesh Yogi, and they came back wearing strange clothing and articulating strange thoughts. Within weeks, every kid on the block seemed to be sitting crosslegged on the floor and lost in space.

Fashion. More than just hair, it was the whole look. It was jeans, an explosion of jeans.When The Beatles finally shed those silly suits that their manager, Brian Epstein, wanted them to wear to make them appear more sanitized and less threatening to mass audiences, they got into jeans and tie-dyed T-shirts, and an era of casualness began. When Lennon donned his glasses in public, every other kid in school went out and bought a pair, needed or not.

Politics. It started slowly. At first, there was only the music. But when it hit, it hit hard. And again Lennon was on the point. He led The Beatles into their antiwar phase, returning his own Order of the Empire medal, awarded The Beatles by Queen Elizabeth. With what was happening in Vietnam and Biafra, he said he felt ashamed to be British.

By this point, he had met Yoko Ono, and they once led 3,000 people in a candlelight march down the streets of Tokyo. Lennon and Ono sat naked in a bed in Amsterdam protesting political conditions around the world. "All we are saying," they sang, "is give peace a chance." But they were never violent, even if their followers in their mobilization were.

In "Revolution," Lennon sang, "But if you talk about destruction, don't you know that you can count me out." By 1969, when Lennon and Ono shared that bed, the antiwar movement in America had reached a zenith that had forced one American president to refrain from running for reelection and set the tone for political races throughout the country.

Undoubtedly, psychologists could have a field day with Lennon. His father had abandoned the family early. Too poor to raise her son on her own, his mother had entrusted him to an aunt and uncle. Later, he would sing about his loneliness and ultimate reconciliation with his family -- a theme that colored much of his work.

Perhaps in that history is a clue to his later appeal to a generation of loners, who could sympathize with his keen sense of futility and despair and his eternal message that only reason and humor could tide one through the ubiquitous tough times on life's way.

What a wit it was! For a generation that craved the philosophy of Marx and Lenin and the films of the Marx Brothers, Lennon kept the black humor quotient balanced.

His wit could be subtle in a raise of the eyebrow and a twinkle in the eye. It could be quick: "One this next number, those in the cheap seats please clap. The rest of you can rattle your jewelry." And it could be snide: "When I feel my head start to swell, I just look at Ringo and know we're not supermen." Like Groucho, he knew the value of never taking one's self too seriously.

He could raise hackles, particularly with his infamous 1966 quote, "We're more popular than Jesus now." It was not a value statement, not an argument, merely the perception of an intelligent man aware of the world around him. It came back to haunt him, as did allegations by Charles Manson that Lennon's song "Helter Skelter" had contained coded messages ordering Manson to ritually murder actress Sharen Tate. And people wondered why John Lennon withdrew.

In recent years, Lennon opted for the safe, middle-age role of house-husband in a stately seemingly impregnable New York City apartment. From 1975 until last month, Lennon tossed only tokens to his fans, not even speaking out publicly last year to scotch rumors of a Beatles reunion at the United Nations.

"What I realized during the five years away was that when I said the dream is over, I had made the physical break from The Beatles, but mentally there was still this big thing on my back about what people expected of me. It was like this invisible ghost," Lennon said recently.

His reentry into the rock world was marked by the release of "Double Fantasy," his latest album with his wife. Breaking out from that album is his No. 1 single, "Starting Over," a silly love song, the kind McCartney is so famous for.

But Lennon didn't intend that the album be a reestablishment of The Beatles. "I don't believe in Beatles," Lennon has sung. No, this album was simply a greeting from an old friend, nothing more.

"I'm really talking to the people who grew up with me," Lennon said in an interview a few hours before he was shot to death. "I'm saying here I am, how are you? How's your relationship going? Did you get through it all? Wasn't the '70s a drag, you know? Well, here we are, let's make the '80s great because it's up to us to make what we can of it."