Lee Chang sub (Hangul: 이창섭; born February 26, 1991) is a South Korean singer. He is the lead vocalist of the South Korean boy group, BTOB. Lee Chang sub debuted as a vocalist of BTOB on March 21, 2012. He also participated in lyrics composition of some tracks by BTOB including, "Last Day", "Killing Me" and "Melody". Read more on Last.fm