Roots of Taeyeon

Jeong Soon-won, better known by his stage name The One is a South Korean singer and vocal coach. He debuted in 1997 as a member the group Space A and released his first solo album in 2002. He has released a total of five albums in Korean and one in Mandarin. As a vocal coach, he has taught K-pop singers including members of Girls' Generation and Super Junior.

Shin Hyo-seob, professionally known as Crush (크러쉬), is a South Korean singer-songwriter and record producer. He debuted on April 1, 2014, with the single "Sometimes" and released his first album Crush on You on June 5, 2014. Fifteen of Crush's singles have peaked in the top ten on the Gaon Digital Chart, with ten of Crush's singles also becoming top five hits including "Just", "Beautiful", "Don't Forget", "Bittersweet", "Let Us Go", and "Rush Hour".

"I'm Not the Only One" is a song recorded by English singer Sam Smith from their debut studio album, In the Lonely Hour (2014). It was written by Smith with Jimmy Napes, who also produced the song along with Steve Fitzmaurice. Capitol Records released it to digital download on 31 August 2014 as the album's third single in the United Kingdom and on 24 September 2014 as the album's second single in the United States; an alternative version with American rapper A$AP Rocky was also released.

"Stand Up for Love" is a song recorded by American group Destiny's Child for their first greatest hits album #1's (2005). It was written by Amy Foster-Gillies and David Foster, with the latter also serving as the producer alongside Humberto Gatica. Musically, the track is a mid-tempo ballad drawing influences from adult contemporary, pop and R&B. Inspired by poverty-stricken children and families, the song was termed the "2005 World Children's Day Anthem", and used in conjunction with Ronald McDonald House Charities to raise awareness of the day. "Stand Up for Love" was released as the lead single from #1's on September 26, 2005, by Columbia Records and Sony Urban Music.

Atlantis Princess is the third Korean studio album by South Korean recording artist BoA, released through SM Entertainment on May 30, 2003. The record spawned three singles, including the Seoul Metropolitan Government promotional single "Lights of Seoul", the title track "Atlantis Princess", and "Milky Way", with accompanying music videos produced for the latter two songs. An overseas version of the album, containing a bonus video CD, was released in several territories in Asia such as the Philippines, Hong Kong and Taiwan.