Cantrell went straight into recording sessions with Dallas Austin, Jimmy Jam and Terry Lewis. In 2001, the singer released her debut album, So Blu, which eventually was certified platinum. The record saw major success when it peaked at #8 on the Billboard 200 albums chart. The album featured the hit single "Hit 'Em Up Style (Oops!)", which peaked at #2 on the U.S. Billboard Hot 100 singles chart and earned Cantrell a Grammy nomination for Best Female R&B Vocal Performance, as well as an American Music Awards nomination. The album also showcases her ability to go into the whistle register with the song "Waste My Time."
In 2003, Cantrell released her second album, Bittersweet. The record failed to reprise the success of her debut album but did earn Cantrell a Grammy nomination for Best R&B Album and managed to enter the Billboard Top R&B/Hip-Hop Albums chart at #8. The album spawned 2 hit singles, "Breathe" and "Make Me Wanna Scream," the first being a collaboration with Sean Paul. Though "Breathe" failed to reach the top 50 in the U.S. , it peaked at number one for four weeks in the UK. It eventually became one of the most successful singles of the year in both Europe and Australia .
In the summer of 2005, a music video for the previously unreleased song, "The Cha Cha" was produced, but never released. Also, in 2005, Hit 'em Up Style: Chart and Club Hits was released without any promotion in the U.S. It was a compilation/remix album containing Cantrell's two biggest hits, some other tracks from the former two albums and some remixes of tracks featured on the first albums. Blu continues to enjoy acclaim by European audiences.