Who said you can't get somethin' for nothin'? The Library of Congress has put a bunch of the recordings from its archives online in what's called the National Jukebox.
About the National Jukebox
The Library of Congress presents the National Jukebox, which makes historical sound recordings available to the public free of charge. The Jukebox includes recordings from the extraordinary collections of the Library of Congress Packard Campus for Audio Visual Conservation and other contributing libraries and archives.