Ask HN: Streaming music and licenses

Other than Youtube, are there any practical options out there? I suppose I can use something like Rdio's API, but this would limit the app to Rdio subscribers. I'm wondering if there is any possibility for smaller-scale apps to negotiate some kind of streaming deal, similar to internet-radio licenses. How do sites like Turntable.fm pull it off? Is the short answer lots of lawyers?

Thanks.