Baek began her music career in 1999, splashing onto the Korean dance scene with her first album Sorrow. The first single, "ì„ íƒ" (Choice), was unusual in that it was one of the first Korean pop songs to feature Latin beats. However, this single proved to be popular and charted very well. She quickly followed this album with a second, Rouge, which came out in April 2000, selling 360,000 copies and cementing her status as one of Korea's most popular female dance artists.
Her career took a major hit, though, in the fall of that same year. A sex tape leaked out on the Internet featuring her having sex with her former manager in a hotel. The tape spread widely on the internet, due to heavy media coverage and South Korea's status as a heavily "wired" country. A major scandal, Baek initially apologized, but then claimed that she had no knowledge of the videotape and refused to remain quiet. She released a third album, Tres, in June of the following year, and it sold a respectable number of copies (the total close to 200,000). The scandal, however, still plagued her; as a result, Baek took a break from the Korean music industry.
Two years after the release of Tres, Baek released her fourth album Smile in September of 2003. Although not a runaway success, it managed to sell a decent number of copies, placing 46th for the year. However, her real comeback occurred in 2006, when Baek released her fifth album Smile Again in March. "ì‚¬ëž‘ ì•ˆí•´" (I Won't Love), her first single from the album, was a ballad, unlike the rest of her Latin-style singles. Although this was a significant change, it proved to be a very popular song, getting to the top spot on certain performance show charts. This change was not a permanent one, as there were many Latin/dance tracks on the album. In fact, the second single has seen Baek going back to her musical roots, as Ez Do Dance is a sexy Latin number. She performed this single until the end of summer 2006, at which point she finished promotional activities for the album. In November 2006, Baek won an award for "Best Female Solo Singer" from the MKMF Awards and was one of the candidates for the "Overseas Viewer" award as well.
On September 7, 2007, Baek's sixth album, The Sixth Miracle, was released, with the lead single "ì‚¬ëž‘ í•˜ë‚˜ë©´ ë¼" ("I Only Need One Love"). She won an award for the album at the Seoul Music Awards in January 2008.
She was scheduled to undergo vocal cord surgery to remove a cyst some time in February 2008. Although there were fears that her singing voice may change, the fear of losing her voice entirely is what prompted her to go ahead with the operation.