015B (Korean: 공일오비) is a South Korean music producer group that debuted in 1990 and went on to become one of the country's most popular acts of the early 1990s.[2][3] The group name which means literally "A crow flies across the sky." It currently consists of brothers Jeong Seok-won and Jang Ho-il, and is known for its "guest singer system," as the group has never had a permanent lead vocalist.[4] The group has experimented with many music genres including pop, pop ballads, synth-pop, electronica, r&b and hip hop.[5][6]
^Lee, So-ra (2017-11-15). "[뒤끝뉴스] 장호일이 밝힌 공일오비 결성 이유" [[Holding Back News] The reason why Gongil Obi was formed by Jang Ho-il]. Hankook Ilbo (in Korean). Retrieved 2018-09-09.
^ abc"Gaon Album Chart". Gaon Music Chart (in Korean). Korea Music Content Industry Association.