From his early days as a wild-haired bassist in metal group Sinawe to his later solo albums, Seotaiji has never stopped pushing the boundaries of popular music, Korean or otherwise. He famously fronted '90s boy band Seotaiji and Boys, whose first single, “I Know,” fused new jack swing and hard rock to create the template for modern K-pop. In his post-Boys career, he's returned to his roots, beginning with metal and alt-rock but gradually moving toward synth-pop and more atmospheric sounds, as heard on 2014's elaborate, arresting “Sogyeokdong.”