public Song Add(Song song)
{
var newSong = song;
this.songs.Add(newSong);
this.songs.SaveChanges();
return this.songs.GetById(newSong.Id);
}
public Song UpdateSong(Song song)
{
this.songs.Update(song);
this.songs.SaveChanges();
return this.songs.GetById(song.Id);
}