In February 2014, Taeyeon joined the ballad group, SM the Ballad, formed by S.M. Entertainment in 2010. In the second album, "SM the Ballad Vol. 2 - Breath", she did a duet with Jonghyun for the song "Breath" as well as her solo song "Set Me Free". "Breath" was the theme of Mnet's mini-drama, "Mimi". The song was also within the top 10 of Gaon and Korea K-Pop Hot 100.