South Korea's first idol boy band came together in 1991, when leader Seotaiji started toying around with MIDI technology, trying to recreate the sounds of American hip-hop. The group's new jack swing-style debut, “I Know,” was an immediate hit, staying at the top of the charts for 17 weeks. Throughout their short but wildly successful career, the group continued exploring and experimenting, fusing gangsta rap with heavy metal and even traditional Korean music, and, in the process, changed Korean pop music forevermore.