Seo In Young made her comeback tonight on 'M! Countdown' with her fierce new track,�"Oh My Gosh". "Oh My Gosh" is an upbeat electro track that showcases the diva's charisma and features a cool shoulder-shaking routine. Armed with an edgy new look, Seo In Young is ready to show the nation what it takes to be one of Korea's top female soloists. Check out her performance below!