They started recording "Millennium" in 1998 and released it in May 1999. It became one of the biggest selling albums of all time taking the number one place in many countries. Their first single from "Millennium'"s follow up album, "Black & Blue", "Shape Of My Heart" was released to radio on October 3. "Black and Blue" recorded first-week sales of 1.59 million copies in the US, making the Backstreet Boys the first artists to back to back million-plus sales of albums.