Cossa has previously served as an executive at the Chamber Music Society of Lincoln Center and New York's Symphony Space, where she oversaw a renovation and expansion. Most recently, she was general director of Glimmerglass Opera in Cooperstown, New York, but she resigned that post last fall because of the illnesses of two members of her family.
Founded in 1939 by composer Aaron Copland and others, the American Music Center distributes grants, publishes a newsletter and the web magazine NewMusicBox.org, and maintains an online music library and a collection of 20th-century music at the New York Public Library.