Tunerec streams the songs you want from a library of thousands
Tunerec, on the other hand, may have a system that will ensure your cloud-based playlists keep working. According to the site, everything is totally legal and all it requires is a little bit of patience. Ok, a lot of patience.
How does it work? Once you're registered Tunerec will automatically begin "recording" tracks into your library. The process seems a bit slow, but only because of the sheer volume. I received my beta code yesterday and currently have 17,056 tracks available and the number is steadily climbing.
I'm assuming that the process is necessary to keep things "legal," though I can't say for certain. There's not a whole lot of information on the site about how it works.
There is, of course, a social element to the service. Invite your friends and you'll be able to subscribe to their playlists and share tracks amongst yourselves.
Overall, Tunerec works quite well. Audio quality is excellent, and I'm very happy with the songs I've got at my disposal. It's currently in closed beta, so head on over and request a code to get started!