U.S. Opera 
Information about American opera composers and their works.
http://www.hapka.com/usoperaOperaGlass: Opera Composers
Alphabetical listing with works and links to better-known composers with details of certain compositions. From Stanford University.
http://opera.stanford.edu/composers/
Arizona Opera Composer Biographies
Provides background, life, and musical details for many of those whose works they have performed.
http://www.azopera.com/learn.php?subcat=composerbios
