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.
Hwang Chan-sung Hwang Chansung (Hangul: 황찬성, Hanja: 黃燦盛, born February 11, 1990), generally known as Chansung, is a South Korean idol singer, rapper and actor. He is a member of the Korean boy band 2PM. Chansung made his debut as an actor in the 2006 comedy series "Unstoppable High Kick", and since then has gone on to star in the Japanese drama "Kaitō Royale" (2011) and "7th Grade Civil Servant" (2013).