I guessed that you had a "not" missing...
Well, we never see what's playing when it's radio. The radio is working like any other radio, when you press 1 on the IR remote for the zone (usually the original remote for the amp there) you get NRK 1, 2 gives you NRK 2 and so on, up to 8, which is the Always jazz channel from NRK. NRK being the Norwegian national broadcasting. Pressing any radio button will pause whatever's playing in the Media Library using MC for that zone, and pressing play for that will stop any radio streaming for that zone. So when I'm listening to heavy metal in the home office and I see that the news is coming on, I press 1 for NRK 1, which also pauses the metal. When the news are over, I press play on the IR remote and the radio streaming stops while the metal starts pounding again. And that's the way it works in any of the 12 zones in the house. Pretty handy!
So the point is that the radio is kept totally separate from the music library. The media library is controlled with NetRemote on Windows phones or Windows computers, or by Gizmo on my Notion Ink Adam or my son's Nook Color Android tablets. I don't let anybody access anything directly, except for myself.