Collabs: Dream (with EXO’s Baekhyun), Don’t Wait For Your Love (with Park Won), Because I Love You (with Kang Seungwon)
OSTs: “Dream High” Dream High OST Part.1 (with 2PM’s Taecyeon & Wooyoung, Kim Soohyun, and JOO) (2011), “Winter Child” Dream High OST Part 2 (2011), “So Many Tears” Me Too, Flower! OST Part 2 (2011), “I Still Love You” Big OST (2012), “Don’t Forget Me” Gu Family Book OST Part.5 (2013), “Why Am I Like This?” The Time We Were Not in Love OST Part.5 (2015), “Ring My Bell” Uncontrollably Fond OST Part.1 (2016), “When We Were” Uncontrollably Fond OST Part.15 (2016), “I Love You Boy” While You Were Sleeping OST Part.4 (2017), “Words I Want To Hear” While You Were Sleeping OST Part.13 (2017), “My Dear Love” Start-Up OST Part.14 (2020), “Inevitable” Extraordinary Attorney Woo OST Part.5 (2022)