Beverly Sills (May 25, 1929 – July 2, 2007), fondly known as "Bubbles" to her many fans, was perhaps the best-known American opera singer in the 1960s and 1970s. She was famous for her performances in coloratura soprano roles in operas around the world and on recordings. After retiring from singing in 1980, she became the general manager of the New York City Opera. In 1994, she became the Chairman of Lincoln Center and then, in 2002, of the Metropolitan Opera, stepping down in 2005. Sills lent her celebrity to further her charity work for the prevention and treatment of birth defects.