This past week I added a song to Radio Free California that hasn't been released. It is a live and improvised performance by Jacob Collier of th Bjork song "Hyperballad". The only place you can find it is on YouTube.
I took the audio and mixed it slightly, and it now plays on the radio station. I figure if it's on YouTube, that's a public release.
In any case, I pay royalties.
I may do the same thing with Joni Mitchell's performance of "I'm Still Standing".