Ha Hyun Woo (Guckkasten) - Hayeoga [King of masked singer]
Ha Hyun Woo (Guckkasten) - Fantastic Baby [King of masked singer]
Ha Hyun Woo (Guckkasten) - Don't Cry (하현우 - 국카스텐)
Ha Hyun Woo (하현우 Of Guckkasten) - 설레이는 소년처럼 (Shy Boy) (The Legend Of The Blue Sea OST Part 4)
Ha Hyun Woo (하현우 Of Guckkasten) - 설레이는 소년처럼 (Shy Boy) (Inst.) (The Legend Of The Blue Sea OST Part 4)