Koh Hyung-seok (고형석), known professionally as CLOUD (구름) or Cloud Koh, is a South Korean singer-songwriter and producer. Born on April 6, 1991, he has been an influential figure in the Korean indie and rock scene. He debuted in 2011 as a keyboardist for the rock band Bye Bye Badman and later joined the indie-pop band CHEEZE in December 2011. His work with CHEEZE contributed to their early success, but he eventually left the group. In 2016, CLOUD launched his solo career, releasing a series of digital singles, beginning with "Cloud 1 'The Way You Make Me’". His unique sound, blending rock, pop, and electronic influences, garnered attention in the indie music community. In 2018, he co-founded the alternative rock band The Volunteers alongside Baek Yerin. The group debuted with the single "Violet" and gained a devoted fanbase for their raw, grunge-inspired sound. CLOUD was also a member of Peaches Label and previously worked under Magic Strawberry Sound, POCLANOS, and RealCollabo. In 2024, he departed from The Volunteers following the conclusion of their contract with Blue Vinyl. His 2021 album, With A Lot of Exaggeration, remains a testament to his artistic depth and musical versatility. Beyond his band activities, CLOUD has contributed to various projects, including drama soundtracks. He participated in the OST for the drama Motel California, releasing the song "Seems Like I Like You" (2025).
