Rainbow Blaxx (레인보우 블랙) was a sub-unit of girl group Rainbow. They debuted on January 20, 2014 with the special album RB Blaxx, their only release with "Cha Cha" serving as the album's title track.

"Alone" (나혼자) is a song by SISTAR. It is the second and title track in their first mini album, Alone.

"Queendom" is a song by Red Velvet. It's the title track for the eighth mini album, Queendom. The EP was released digitally by SM Entertainment on August 16, 2021, and physically on August 17, 2021.

The music video of "Fancy" was uploaded online on April 22, 2019. The visual introduces individual members in vibrant, stylish looks surrounded by vivid backdrops while the group itself switches off between bold black numbers and colorful "Fancy" outfits, much of which features Chanel's signature double "c" logo. The music video alternates between feelings of decadence and playfulness, largely thanks to the CGI graphics that bolster the nine member's performances. All the while, the group shows off powerful choreography.[1] In the same day, the music video became the seventh-biggest debut on YouTube, garnering over 42.1 million views in a single day.[14] The music video was ranked third place on 2019 YouTube's Most Popular Music Video in South Korea.[15] It also ranked at No. 10 on 2019 YouTube's Top Trend Music Video in Japan.