AS A LITTLE GIRL, MARY ELLIN Barrett worshipped her father, Irving Berlin. Yet it wasn't until she was 15 that she discovered how widely that sentiment was shared. "The opening of his musical This Is the Army, on July 4, 1942, was a night when things came together for me," recalls Barrett, now 67. "He was onstage, and the whole theater was on its feet cheering. Not just for This Is the Army, but for his whole history, for what he had given us."

What Berlin gave us was an extraordinary musical legacy, not just "God Bless America," "White Christmas" and "Cheek to Cheek" but also a rich songbook spanning nearly a century. Among his compositions were "Alexander's Ragtime Band" (1911), "Always" (1926) and "Puttin' on the Ritz" (1929), as well as music and lyrics for 18 films (including Top Hat) and 19 Broadway musicals (among them Annie Get Your Gun). As his poker buddy composer Jerome Kern observed, "Irving Berlin has no place in American music. He is American music." By the time of his death at 101 in 1989, Berlin, who could not read music and called his gift "a little knack," had composed 1,500 songs and made tens of millions.

A Daughter's Memoir (Simon & Schuster), Barrett's newly published, affectionate reminiscence, takes vigorous issue with a few long-standing myths about the man: No, says Barrett, Berlin was not a skinflint, an absentee father or ungenerous with other songwriters. Barrett, a journalist and author of three novels, including Castle Ugly, intertwines happy domestic memories with vivid glimpses of her father's artistic struggles. "Those songs that seemed so effortless were the result of long nights," she says. "Every now and then one would come fast. But my mother would say he sweated blood over them."

Barrett grew up steeped in tales of her parents' long love affair. Their early years had been a study in contrasts. Berlin, a Jew, was born Israel Baline in Russia. He moved to the U.S. with his family when he was 5, and by 14, he was hawking songs for pennies on street corners in lower Manhattan. She was Ellin Mackay, the Catholic heiress to a silver-and-telegraph fortune who grew up in Roslyn, N.Y., with a houseful of servants and her own personal maid. Berlin became a singing waiter in 1905 and two years later published his first song, "Marie from Sunny Italy." By the time the pair met at a dinner party in 1924 and amused each other with their repartee, Irving had a Broadway hit with his long-running Music Box Revue; Ellin, a post-debutante, would write her first article on life among the rich for The New Yorker in 1925. At 36, Berlin was also 15 years older and a widower—his first wife had died of typhoid fever five months after their 1912 wedding. "From the time I was a child, I knew that my father had not been eager to get married," Barrett recalls. "My mother had pursued him relentlessly." When they did wed in 1926, Ellin's father, Clarence Mackay—owner of the Postal Telegraph Cable Company—was so enraged that she had married a Jew, says Barrett, he disinherited her. They eventually reconciled.

Nothing, though, could separate the Berlins. "They honeymooned in Europe," says Barrett, "and had such a romantic time that when it was over, my mother sat on her trunk and cried." Mary Ellin, first of their four children, was born in 1927, and her father marked the occasion with a happy new song, "Blue Skies." From the beginning, Barrett led a life of privilege: chauffeured cars, private schools, summers in the plush enclaves of Montauk, on Long Island, or Santa Monica. "My father always handled this lavish living in a down-to-earth way," says Barrett in her modest, book-filled apartment on Manhattan's Upper West Side. "He would say, 'This is great, but don't count on it.' There was a real sense that we should appreciate what we had." Religious holidays, given the Berlins' decision to expose their daughters to both Christianity and Judaism, were always special for Barrett and her sisters, Linda Emmet, now 62, and Elizabeth Peters, 58. They celebrated Easter, Passover, Christmas and Hanukkah. "I have this picture of my Catholic mother sitting there and reading us the story of Judas Maccabaeus," says Barrett, adding, "I always thought of myself very distinctly as a 'half.' "

The only troubling notes that Barrett remembers were her parents' insomnia—they kept separate bedrooms as a result—and their periodic bouts of melancholia. Her father's first depression followed a creative dry spell in the '30s; her mother was tortured by the memory of her infant son's crib death in 1928. "I had a sense that these were frail people," says Barrett, "especially my mother, who wept a lot and in those days was, as my father said, 'Niagara Falls.' "

For the most part, though, life at home was upbeat, with Berlin himself a strong and energizing presence—sometimes even shockingly so. When Barrett was a teenager, she writes, Berlin had a "habit of wandering about the third floor fresh from his bath, a towel wrapped around his waist, and his hat on to keep his slicked-down hair in place ('Daddy,' I shrieked, if I came upon him thus, in the company of a friend, and he would duck back into his bedroom or his bath)."

The Berlins played host to a glittering guest list, including composer George Gershwin, director George Cukor, MGM star Norma Shearer and King Kong's, Fay Wray. Barrett remembers Fred Astaire as "Mr. Astaire, who'd come to our house without his toupee on. He would look very comical, a pleasant, balding man who arrived to play gin rummy with my father." And Joan Crawford was "my mother's glamorous friend with the deep suntan" who, long before she became Mommie Dearest, "would flop down on my sister Linda's bed, kick her shoes off and read her a story."

In 1949, fresh out of New York City's Barnard College, where she earned a degree in music, Barrett married—much to her overprotective parents' dismay. By 1950 she was single again and working as a researcher at TIME magazine. There she met Marvin Barrett, now 70, who was then a young editor. They wed in 1952 and gave the Berlins four grandchildren—Elizabeth Matson, now 40 and a former researcher and librarian; Irving Barrett, 39, an artist; Mary Ellin Barrett Lerner, 38, a journalist; and Katherine Swett, 34, a Ph.D. candidate at Columbia University—and eventually five great-grandchildren.

Taking title to her own life in the late '40s left Barrett little time to notice that her father was on the edge of another depression. He had exhausted himself with a two-year European tour as the star of This Is the Army, then jumped into composing Anme Get Your Gun in 1946. And though Berlin eventually wrote another rousing Broadway show, Call Me Madam, in 1956, his musical instincts, surefire for so long, had begun to falter. His last effort, Mr. President, in 1962, closed after a mere 265 performances.

Berlin himself would survive another 27 years. "It was painful writing about these years, because my father didn't have a glorious old age," says Barrett. "He could still compose songs, but as his energy diminished, he couldn't do shows. Also, after 60 years of writing, it must have been flickering out. That was hell for him to live with. He had always had a private side, and it just took over."

Yet even in their reclusive old age, says Barrett, her parents continued to cherish each other. When Ellin Berlin, author of the best-seller Lace Curtain, died of a stroke two months after Living's 100th birthday, Barrett and her sister Elizabeth went to their father's bedside to break the news gently. "It was the hardest thing I have had to do in my life," she writes. A little more than a year later, Berlin too was gone.

"His was an amazing life," says Barrett, who admits that, while she will always have "Blue Skies" and the legacy of Berlin's musical genius, she deeply misses his presence. Yes, she says, he had his flaws, "but I feel a great sense of privilege at having been his daughter."