I admire the folks at project playlist. They've developed a service that carefully navigates copyright infringement, at least how the recording industry plays that game today.

I'll ignore their playlist sharing. While that makes for a nice title, that's not why people visit.

Here is what Project Playlist does:
> Search for web-based music. While the files may be illegal to host and download, it is not illegal to search for and display them. As long as you can't download them.
> Stream found music files. The site says that it legally "pay[s] royalties to songwriters and music publishers." Streaming, good. Download, bad. Can you sing that tune?
> Take down illegal files. Of course this is after they receive a complaint from the copyright holder. Not before they display the results such as if they were using a system to filter copyrighted content.

What it doesn't do:
> Provide a download link to web files. See, that's how they stay clean. On the other hand, they do publish the web URL. Wink, wink, nudge, nudge. So you can directly play and download the file. Just copy and past the URL into your browser. Now it's a less efficient and poorer user experience than using P2P software. But it does work as I can personally attest.