효연 (HYOYEON) – Mystery
Track 01 from Single "Mystery - SM STATION"
Release Date: 2016.12.02
효연 (HYOYEON) – Wannabe (Feat. San E)
Track 01 from Single "Wannabe (Feat. San E)"
Release Date: 2017.06.01
효연 (HYOYEON), 민, 조권 – Born to be Wild (Feat. 박진영)
Track 01 from Single "Born to be Wild - SM STATION"
Release Date: 2016.08.26
예은 (CLC), 전지우, JAMIE (제이미), 치타 (CHEETAH), 효연 (HYOYEON) – WITCH (마녀사냥)
Track 01 from Single "GOOD GIRL Episode 3"
Release Date: 2020.06.19
효연 (HYOYEON), 이영지 – I Do What I Want
Track 05 from EP "GOOD GIRL FINAL"
Release Date: 2020.07.03
효연 (HYOYEON), 치타 (CHEETAH) – 털어 (TURL)
Track 04 from EP "GOOD GIRL Episode 1"
Release Date: 2020.06.05
에일리(AILEE), 효연 (HYOYEON), 전지우 – GG
Track 04 from EP "GOOD GIRL Episode 4"
Release Date: 2020.06.26