SSU Library: two online listening libraries.
Boston Public Library: nine online listening libraries - all available outside of the Boston Public Library with an ecard.
See Boston Public Library Music.
Library Web Page:
Naxos
Database of Recorded American Music
Free Resources
Boston Public Library Electronic Resources: Music - this includes Music Online Listening
Sign up to use these resources: http://www.bpl.org/general/circulation/ecards.htm
IMSLP
Library of Congress: Music
Spotify
YouTube