I hadn't heard of Zune Pass before. My first thought was that I could not get music to my stereo due to digital rights management issues. However, I could still listen to music on my computer and listen to different music at work.
I tried, but I could not stump Zune Pass with music I wanted to explore. I figured that there was no way that they would have Woody Guthrie, but they did. The 14 day free trial will be a good way to explore the service.
Due to DRM issues, I never even buy iTunes music. I buy the CD and burn a lossless version to stream to my stereo and lossy version for my iPod. I would still stick to that method, but could still find the music on Zune Pass.
You may have heard Dan Wilson before with the song "Closing Time" that he did with Semisonic. Prior to that he was in Trip Shakespeare. None of those songs became a radio hit, except local stations will play "Snow Days" during a heavy snow fall.