Number Nine is a song by South Korean girl group T-ARA, released in 2013 as the title track of their mini-album Again. Built around a repeated, chant-like chorus, it became one of the group's signature dance tracks during the second generation of K-pop. Fans shared dance covers, stage performances, and short edits online, keeping the hook familiar long after its chart run. Today it is still used in fan videos and dance content as a nostalgic, high-energy nod to that era of Korean pop music.