Her lawyer, Mark Geragos, posted the 27-second video on Twitter, which sees the 28-year-old pop star crooning over a melancholy guitar, reported E! online.
"Oh, I don't know what I would do without you, oh no. I don't know where I would be without you," she sings.
Earlier this week the "TiK ToK" hitmaker also posted a lengthy thank you message on her official Facebook page.
Kesha mentioned in a lawsuit which she filed in 2014 that Luke sexually assaulted her. The music producer has repeatedly denied the accusation though.