AMG All Music
Comprehensive database of information about popular and classical music recordings and movies. Includes bibliographies, reviews, essays, and samples of recordings
Gramophone
E-newsletter includes reviews of new releases, recommended recordings, news features, competitions, and awards.
Recorded Sound Reference Center
Access the commercial and archival audio holdings of the Library of Congress, including its recorded sound catalog, online recordings, and NBC Radio Archive.
Musical Heritage Society
Society bought out 2011 by Passionato; links now dead at both www.musicalheritage.com and www.passionato.com as of 15-Dec-2016; look for news online.
Berkshire Record Outlet Inc.
Closeouts and overruns of classical music labels. Also opera, film scores, original cast, jazz, blues, and world music recordings.
GEMM
GEMM has gone out of business and shut down their website as of July 2015.
Rare and collectible LP's, 45's, 33's, CD's, cassette tapes, and memorabilia from stores worldwide.