Timing is the fourth Korean mini-album by the leader and main rapper of what boyband?
Kim Hyun-joong Kim Hyun-joong (; born June 6, 1986) is a South Korean actor and singer, and the leader and main rapper of boyband SS501.
Lee Sung-jong Lee Sung-jong (Hangul: 이성종; hanja: 李成種; born September 3, 1993), commonly known as Sungjong, is a South Korean singer. He is the vocalist of the South Korean boy band Infinite under Woollim Entertainment. He is also the vocalist of Infinite F.