Hmm... I haven't heard of the site before, and it doesn't work when I try to visit now. I hit "play track" and it just doesn't go anywhere. I need more information on exactly WHAT it is that radioblog does. I mean, if you're uploading a song to them, and then merely linking it on your site (that is, not hosting the actual file here) then I'm might be inclined to think it's okay, as the legal issues become theirs. If, however, you're only talking about doing something like that... I don't know, we're in some fine-line territory here with copyrights and legal issues. Most stuff online, even the seemingly legit stuff (like internet radio stations) often isn't technically legal. I see no links on radioblog about the legal/license issues.
Give me more information, on EXACTLY what you plan to do, and by that I mean, where is the song hosted, where is it linked, how do visitors play it, is it downloaded or truely streamed only, etc.