Kesha Lends the Hook to Macklemore's Reflective New Song, 'Good Old Days' -- Listen!

Kesha and Macklemore are reminiscing about the "Good Old Days."

The Rainbow singer delivers the hook on the newest song from the Gemini rapper's upcoming album, letting her voice soar over a piano ballad that is somehow both somber and uplifting in tone.

"Someday soon, your whole life's gonna change," the 30-year-old singer croons in the anthem about appreciating the now. "You'll miss the magic of these good old days."

Check out the song below.

Gemini drops on Friday.

Meanwhile, Kesha recently put out her first solo work in quite some time.

Watch the video below for her emotional essay about her single, "Praying."