"Dancing Queen" is a song by Girls' Generation, released on December 21, 2012 as a pre-release single from their fourth Korean album, I Got a Boy. It is a remake of British singer Duffy's song, "Mercy."
The song was recorded in 2008, initially slated as the title track for the group's first Korean mini-album, but due to last minute copyright issues, the song was unable to be released. "Gee" was eventually chosen to replace the song, both as a lead single and title track.
Most of the music video was filmed in 2008. The outfits and the concept are very similar to "Gee", likely due to the fact that "Dancing Queen" was supposed to be the title track for their fourth Korean mini-album, but was scrapped and replaced with "Gee".
The music video has a time machine plot. Opening with the members in a pink room, Yoona opens up a gift that is revealed to be a small time machine. It takes the members back from the year 2013 to five years earlier, 2005, to a retro-style diner. Tiffany turns on a jukebox, and she and Jessica sing the song's intro in English. During the bridge, the members throw a party while dancing in groups of three while Tiffany approaches a DJ telling him to play a song. After the song ends, the group is back in the pink room.