Why can’t play radio feature on some songs? A station doean’t exist?

[EMI315]

I’m a premium member. I recently found some rare hit that I really like. But for some songs, radio feature is not available. It says “ a station for this song dosen’t exist right now”, but if not exist, how can I create one? Is there anything missing in the song? If I can’t do it myself then who can create a song station? 

[EMI315]

Here’s my screen shot, hope it helps to answering my question. Thanks!