Rookie ballad quartet BoM ('Blooming of Our Music') has finally made their debut on today's episode of 'M! Countdown'. Comprised of members�Raewon, Sechang, Tagoon, and Yua, each boast a long history of experience in the industry. Raewon released two digital singles in 2010, and Sechang was a child actor as well as a contestant on�MBC's 'Birth of a Great Star'. Rapper Tagoon (better known as Mino) was a former Block B trainee, and can be heard in several underground mixtapes (Zico, Hanhae). The title track of their debut single, "Without You", was produced by composer Yang Jung Seung, who's known for working with artists like Jo Sung Mo, Ivy, and KCM. This R&B ballad features a stunning 40-person orchestra, as well as a piano melody that evokes a sense of sorrow. The song also centralizes around the members' vocals, whose strong performance tells the tale of one man's unforgettable memories of his lost lover. Check out their debut performance below! Source: Daum Music