Yoon Hyung Joo is a South Korean folk singer, lyricist and composer. He graduated from Gyeonggi High School and later attended the school of Medicine at Kyung Hee University but dropped out. Yonsei University awarded him an honorary bachelor's degree in Medicine and Kosin University awarded him an honorary Ph.D. in Mission Studies. He dropped out of medical school due to his passion for music and, alongside Song Chan Sik, dominated the folk music scene and the C'est Si Bon music lounge in the 1970s with the duo called Twin Folio. The movie "C'est Si Bon" shows part of his youth with actor Kang Ha Neul portraying him. He was banned from appearing on TV for 3 years after being found guilty of drug possession, an fairly common activity among musicians at that time, but resumed his activities in 1979 without serving any prison time and was not forced to quit his career like it happened to other singers. The duo split up due to the intense pressure from Yoon's father, who was a professor and was opposed to his son not going to college. He was also a radio DJ and a TV host for several shows and composed the music for many TV commercials. He is now semi-retired but still makes a few TV appearances and performances each year.

(Source: Korean = Namu Wiki || Translation = MyDramaList) Edit Biography