Dijuluki Penyanyi Bersuara Bak Malaikat, Beriktu Profil Sung Si-kyung

2. “You Are My Spring” OST Secret Garden (2010)

3. “Every Moment of You” OST drama My Love from the Star (2013)

4. “Fondly, Goodbye” OST Moonlight Drawn by Clouds (2016)

5. “Somewhere Someday” OST The Legend of the Blue Sea (2016)

6. “If I Could Be By Your Side” OST The Crowned Clown (2019)

7. “Leaning On You” OST Tale of the Nine Tailed (2020)