On today's episode of KBS's 'Music Bank', veteran soloist Kim Wan Sun made a powerful comeback with "Be Quiet", which featured a guest rap from�B2ST's Junhyung! Junhyung not only produced her album, but starred in her music video as well. Her electronic dance track is both trendy and addictive, and is a testament to Kim Wan Sun's everlasting talent. Junhyung commented, "I was really excited to be able to work with such a great senior, who's an icon representing a generation of her own. I'm going to work hard to present a good image on stage with her, so please give us your love." Check out their collaboration below! Source: Newsen