The Free Music Archive is a website that hosts and distributes music under creative commons licenses or that's entered the public domain. It was created from WFMU-FM and provides music from Post-Rock to Blues; though it does tend toward the more electronic, experimental, "is this even music?" side of things. That aside, the archive has dozens of curators who work to bring music in from all over the world and blog about their work on the site. If you like free stuff (and you know you do) you shouldn't even have read this far. Click the link at the top.