A Norwegian musician known as Binarpilot is not only unique in a musical sense, but also in his pro-piracy stance. He actively supports piracy as a means of distribution, and currently has all of his music up on his website for free. I recommend you read the full article, as he does have a point.
"In the interest of getting a point across, I'll sum it up for you: It's not hurting the artists, it's hurting the industry behind the artists. And that is, in my opinion, the beauty of it; Contrary to what they want you to believe, piracy is (if anything) saving music, because it's bringing a corrupt and exploitative machine down to its knees."
Here's a really good documentary about copyright laws. If you're into sampling, you NEED to watch this.
"Immerse yourself in the energetic, innovative and potentially illegal world of mash-up media with RiP: A Remix Manifesto. Let web activist Brett Gaylor and musician Greg Gillis, better known as Girl Talk, serve as your digital tour guides on a probing investigation into how culture builds upon culture in the information age.
Biomedical engineer turned live-performance sensation Girl Talk, has received immense commercial and critical success for his mind-blowing sample-based music. Utilizing technical expertise and a ferocious creative streak, Girl Talk repositions popular music to create a wild and edgy dialogue between artists from all genres and eras. But are his practices legal? Do his methods of frenetic appropriation embrace collaboration in its purest sense? Or are they infractions of creative integrity and violations of copyright?
This documentary is released under Creative Commons Attribution - Noncommercial 3.0 Unported license."
Its pretty much about Nine inch nails making their album the slip, available to the public for free. They're actually encouraging people to remix it and share it with others...
Jamendo is a music website and a community for free and legal music downloads under Creative Commons licenses. Includes an additional pro-shop, where companies can pay artists for commerical use of their music.
If you want legal stems for EDM music. Beatport throws you a bone every now and then. They have monthly remix competitions where they have an artist release the stems for one of their tracks on beatport. Artists that have done this is Bingo Players, Zedd (who actually got signed by winning a beatport contest), Skrillex, Above & Beyond, Cedric Gervais,John Dahlbäck.