Mood Ring (By Demand) is a song from Britney's ninth studio album, Glory. Initially available solely as a bonus track for the Japanese edition of the album, it was later released as the promotional official worldwide single from the 2020 re-release of the album.
On August 10, 2016, DJ Mustard confirmed the track via Twitter.
On August 26, 2016, "Mood Ring" was announced as a bonus track for the Japanese edition of Glory. It would not be released in any other countries.
On May 29, 2020, an official re-release of Glory was released worldwide, after a #JusticeForGlory hashtag got the album back to the top of the iTunes pop chart. The re-release featured "Mood Ring (By Demand)" as a new single, making it the third official worldwide single from the album. The "By Demand" in parenthesis was added to the song title to acknowledge her fans' work.
On May 30, 2020, "Mood Ring (By Demand)" peaked at number one on the iTunes US chart, despite having been recorded four years ago.