Furler prefers to be detached and cheeky about how she earned it all. Several times during our interview, she repeated the phrase “I can’t believe I got away with it,” referring to what Alex Macpherson, the pop-music critic, calls “these vague, inspirational, cliché ballads.” This type of music would have seemed deeply out of place on one of Furler’s five hyperpersonal, bohemian and soulful albums. And she certainly never aimed to write these “victim to victory” ballads when she was starting out. After all, Furler was born to an artist and teacher, Loene Furler, and Phil B. Colson, a blues guitarist known as Philby, in Adelaide, Australia. According to him, their family life was a creative idyll, filled with hippies and feminist musicians, living in “connubial bliss,” at least until the unmarried couple split and he moved to Sydney when Furler was 10.

Furler didn’t have much of a relationship with her father after he left, but she had a natural gift — that voice — and wanted to follow him into the business. In 1993, when she was 17, Furler was working at an Adelaide cafe when she happened upon Crisp, a local hip-hop/soul band along the lines of the Roots. “I’ll be your singer then,” she told a guy she knew in the band. When she showed up at rehearsal, Jesse Flavell, Crisp’s founder and former guitarist, recalls, “she opened her voice and we all kind of stopped in our tracks. And we all felt, O.K., this is going to work.” It was also clear, however, that Furler did not have the extroverted persona of a natural performer. She relied on booze to help get her through live shows, and her alcoholism eventually intensified, years later, after she left the band, when her boyfriend was run over and killed by a taxi in London. (Furler’s mother broke the news the day before she was to fly and visit him.) Almost nobody knew about these personal demons when Furler later hooked up with Zero 7, a British trip-hop duo who developed a dedicated following in the late ‘90s but lacked a lead singer. Furler sang memorably on a few of their albums and caught the attention of a couple of Hollywood music supervisors who would later pitch “Breathe Me” to the producers of “Six Feet Under.”

Trying to become a pop star is not for healthy people, or sick people who want to be healthy. The hours are irregular, the sleep is intermittent and the drugs and alcohol are plentiful. Furler began to realize she had an addictive personality. Whenever she quit drinking, she would invariably become hooked on raw food or Nutella. And after she was given a diagnosis of bipolar disorder, she took antidepressants and painkillers, including Xanax and OxyContin, and eventually became addicted to those too. “I was in the back lounge, high on Xanax and alcohol, watching every episode of ‘E.R.’ from the beginning,” she said of her years on the road. “When you’re in a different place every day, there’s this kind of madness that sets in. It’s easy to get away with getting high, because everybody’s drinking on the road. None of my friends thought I was an alcoholic, and neither did I.”

When she eventually sobered up, after her suicide attempt, Furler found that her struggles were oddly valuable in her second career. She excelled at one of a pop songwriter’s main jobs: connecting with impossibly famous, needy people. She was a natural at listening to stars talk about their own insecurities and quickly turning those feelings into catchy hits. Furler and Aguilera, a fan of Zero 7, clicked in the studio after she helped the singer write four songs, including “All I Need,” about her son, Max. “She’d sit and have a mini-therapy session with Christina,” says Sam Dixon, who co-wrote and produced the songs. “I would leave the room. That was secret ladies’ business.” Britney Spears, who worked with Furler on “Perfume,” among other songs, also felt a close connection with her. “I fell in love with the way she looks at life,” she says. “There is a bit of darkness somewhere in there, but it doesn’t come across in a frightening way.”

Last August, Lea Michele, a star of Fox’s “Glee,” requested that Furler help her record songs for her debut album. Michele wanted to write one personal song about her co-star and boyfriend, Cory Monteith, who died the previous month of a toxic combination of alcohol and heroin. During the two hours they spent together over coffee at a Los Angeles studio, she spilled out the story to Furler, who took notes, then played Michele a work-in-progress song on her iPhone. Michele began to sob on the sofa, and Furler eventually wrote “If You Say So,” based on the young star’s feelings. “Maybe it was because I have a dead boyfriend, too,” Furler said later, offhand, while recounting the moment. Then she paused, no longer cheeky. “Maybe I have some shame around it,” she said. “Maybe I’m embarrassed because I’m writing something so cheesy. Then something like that experience will happen, and I’ll realize maybe I’m not as stupid as I thought — and maybe people aren’t as stupid as I think. It occurs to me that there is value to what I do.”

When we first met, Furler immediately blurted out that she had scheduled one of our interviews during a pizza party she was planning for her friends in order to “avoid intimacy” with me. I knew that she was freaked out by the idea of talking to a reporter, but Furler’s defensiveness or anti-fameness, however omnipresent, belies the fact that she is reflexively intimate. As we prepared for the pizza party, she started talking, casually, about her failed suicide attempt. She was sitting in her New York apartment on a September day, she recalled, watching “Real Housewives” on Bravo, when she thought she needed something “to relax.” Furler had been sober for a few years then, but she decided it was time to take the drugs she bought months earlier. Her plan was to check into a fleabag hotel around the corner and ingest every pill she had. She wrote a vague note to her dog walker, she said, and another note to a hotel manager requesting an ambulance: “I’ve killed myself and I don’t want you to have to suffer seeing my dead body.” When her friend called, though, she thought better of it.

Despite her success, despite her new famous collaborators and friends, despite the fridge that David Guetta built, Furler still isn’t comfortable with fame. She refused to pose for a photograph for this article and recently appeared on the cover of Billboard with a bag over her head. But the 12-step program encourages people to “share,” she says, and she now tries to be more open about herself. As I dusted mushrooms and Furler washed kale in the sink, she said she spent five years not talking to her dad, who she believed was jealous of her career. At one particular point, she says, she offered to sing backup on the album he had been working on for more than a decade, and he snapped, “It’s my record, and you’re not on it.” (Colson denies this.) A few years later, Furler wrote him a series of resentful letters, including one asking why he moved away when she was 10.