There are, at least, three bands known as 2AM. 1) 2AM is a South Korean four-member ballad boy band under JYP Entertainment. The members are Jung Jinwoon , Jo Kwon, Im Seulong, and Lee Changmin. 2AM is one of the two subgroups branched out from the eleven-member (before Jaebeom's departure) boy band One Day, the other being 2PM. They officially debuted on July 11, 2008 on KBS's Music Bank, performing their debut song "This Song".