Astonished by the 16-year-old's voice, Fair suggested her for a song in Mulan that required the singer to hit a high E, an octave above middle C — something few singers have the range for.
"It was all about one note. And being able to hit it," she remembers.
Aguilera nailed the note — and landed a recording contract with RCA.
Her first single, "Genie in a Bottle," came out a few months later, then the album Christina Aguilera, which went platinum — selling a million copies — in just four weeks.
The initial rush of stardom was hard. "I was — whoosh! — just everywhere at once," she says: traveling and performing constantly, doing publicity interviews, photo shoots, concerts she didn't even know she had agreed to.
She managed it, but the stress took a toll. "I was being overworked and I definitely needed to take a minute for myself," she says. "I felt on the verge of cracking."
Wanting to Break Out
Despite all her success, Aguilera was unhappy — not just about the workload, but about the direction her music had taken. She had been fashioned into a neatly buffed pop princess — and she hated it.
Now turning 21, she felt she had failed to accomplish what mattered most: to be true to herself. She told her record company she didn't want to make "Genie in a Bottle, Part 2."
"I'm not that girl," she says. "I think music should be honest, and about who you really are. I would be fake if I tried to do that again."
The pop princess was dead, and with Stripped, Aguilera was reborn as a darker, edgier artist, with a new moniker: X-tina.
Photos, videos and tabloid accounts presented someone many saw as an unfit role model, and frankly as a sellout: a talented artist taking the easy way to commercial success. But Aguilera is defiant.
"It's just me being me, that's all it is …. I'm always going to be changing and evolving," she says. Aguilera says she was the also the victim of a double standard: that when male artists make raunchy videos, no one complains.
"I think it scares people when a woman is comfortable with her body, comfortable with herself, her sexuality," she says.
Baring Her Soul
One of her new songs, "I'm OK," suggests that the album's title refers to not just her body, but her soul.
In the song, she describes her father's violent temper, and emotions she had not dealt with since childhood.
"It's so emotionally and psychologically damaging, it sticks with you," she says.
She recorded the song in one take, lying on the floor of the studio.
"I'm crying on the record, half crying, trying to hold back my tears. It was the hardest thing I've ever had to sing."
When her mother heard the song, it reminded her of the screams she would hear from her little girl when her parents were fighting. "Those same sound effects actually happened," Kearns tells 20/20.
Aguilera says she wrote the song not to hurt her father, who lives on the other side of the country, but as her own "healing process."
The song has not fostered a rekindling of their relationship, but it did prompt a letter from her father. "He wrote, a letter to me expressing that I had to do it to heal myself, and he made a mistake. He knows it."
This story was originally broadcast Feb. 14, 2003.