Black Flag is an American hardcore punk band formed in 1976 in Hermosa Beach, California, United States, largely the brainchild of Greg Ginn, the guitarist, primary songwriter and sole continuous member through multiple personnel changes. Keith Morris was their original lead singer. He left the band suddenly in 1979 to form the well-known band, Circle Jerks. Ron Reyes was the second singer for the band, but decided to leave the band not too long after.