This song is about the beauty and pain of Earth. It is about the Evil controlling the land, and the people being happy anyway. The people hear the calling and they begin to know the plan of Creation but they still wonder because they are not being saved yet. They are calling to heaven for an Angel to save them.
Its about the evil hiding and us remaining strong - playing the tune till death and a metamorphosis into the Angel or the Angel finally arriving. And still they call the Fifth Angel they call him Angel.