First thing is first... You don't set the player.SoundLocation property by calling the .Equal method. You would simply set it like player.SoundLocation = "location Uri"; The way you have that coded would return true or false whether the current sound location matched that string never actually setting the sound location.
However, you can't really do that because you embedded the sound in a resource file. You need to use the resource manager to load the resource from the .resx and then load it into the player. Something like this should do the trick:
ResourceManager manager = new ResourceManager("Resource1",typeof(App).Assembly);
Stream mediaStream = manager.GetStream("Age_Of_Mythology_Soundtrack___Eat_Your_Potatoes");
SoundPlayer player = new SoundPlayer();
player.Stream = mediaStream;
Of course, the resource file has to be compiled as an embedded resource.