“그런 날 [Disappear]” is from Niel‘s second solo album, Love Affair (2016). A member of Teen Top, Niel showcases his vocals on this track. Who knew Niel could get down like that?
Source: YJzKP. “NIEL(니엘) – 그런 날(On that day)[LOVE AFFAIR…](MP3).” YouTube. 15 Jan 2017. https://youtu.be/ccAuU783NKI, (21 Jan 2017).