Is the XNA 3.0 audio stuff implemented? It doesn't seem like it's working.

Content.Load<Song>(filename) does seem to work, and returns me a physical object; albeit all the properties throw a NotImplementedExxception.

Then MediaPlayer.Play(song) with a Song instance throws a NullReferenceException.

Am I missing something? Is this supposed to work? (FYI, I also can't figure out what combination of path and build action to make SoundEffect find the file either.)

Try setting the build action for the song to Content instead of Resource. I did this on XNA 4.0 with an MP3 and it worked, but it kept looping. Using MediaPlayer.Stop() would hopefully fix the problem.