The singer, who turned 39 on Wednesday, debuted the previously unreleased song, “Swimming in the Stars.”
The tune was originally recorded for her 2016 album, “Glory” but not included.
Spears teased the release of the song last month and it’s the first new music from the singer in quite some time.
Spears announced last year that she was taking an indefinite work hiatus. She is currently embroiled in a legal battle with her father over her 12-year-conservatorship.