In 2005, at 18, Kesha was signed to Dr. Luke's label, Kemosabe Entertainment, and his music publishing company, Prescription Songs.[18] Kesha later sang background vocals for Paris Hilton's single, "Nothing in This World".[16] Dr. Luke became preoccupied with other incoming projects, having enjoyed success writing and producing for pop star Kelly Clarkson's album, Breakaway. Kesha then signed with David Sonenberg's management company, DAS Communications Inc., in 2006, hardly interacting with Dr. Luke after that. DAS was tasked with obtaining a major label record deal for Kesha in a year’s time in exchange for 20 percent of her music income, with her having the option of ending the relationship if they failed.[20] She worked with several writers and producers while at the company and ended up co-writing Australian pop group The Veronicas' single, "This Love" with producer Toby Gad.[18][21] While furthering her career in studio, Kesha earned her living as a waitress.[4] She adopted the dollar sign in her name while struggling to get by as an ironic gesture.[19]
Kesha appeared in the video for her friend, Katy Perry's single "I Kissed a Girl", and sang background vocals for the Dr. Luke-produced song, "Lace and Leather" by Britney Spears in 2008.[22] DAS soon attracted the attention of songwriter and A&R Kara DioGuardi, who wanted to sign Kesha to Warner Bros. Records. The deal fell through due to her existing contract with Dr. Luke's label. In September, she terminated her contract with DAS, reuniting with Dr. Luke.[18][20] Kesha gained exposure in the mainstream media in early 2009 after appearing on rapper Flo Rida's number one single, "Right Round".[23] The collaboration happened by accident; she had walked into a recording session for the song with Flo Rida and Dr. Luke.[24] Flo Rida wanted a female voice for the song; Dr. Luke then suggested Kesha for the part. Flo Rida liked the end result so much that they did two more tracks.[25] However, she is not credited for her feature on the United States release of "Right Round" and did not collect any money for the part.[18][23] She also refused to appear in the video, explaining to men's magazine Esquire that she wanted to make a name for herself on her own terms.[22]