A lot of people leave online files lying around where Google can index them,
including music files. By asking Google the right questions you can find these online
You'll find that the vast majority of results are inaccessible, others are fake, but a few are the real deal. On this page, you'll see some examples of sites that work. You'll quickly learn how to tell the difference between them and the fakes.
* Lesser known musicians return better results.
Click right to the 9th or 10th page of results to start unearthing the good stuff.
Credit to tech-recipes for the original search queries.