Confused by cpp classes

SongController.h:
	#ifndef CONFIG_H
	#define CONFIG_H
	#include "Song.h"

	class SongController
	{
	    public:
	    Song song;
	    SongController();

	};


Song.h:
	#ifndef CONFIG_H
	#define CONFIG_H
	class Song
	{
	    public:
	    Song();
	};

The cpp files simply include their respective header file and define blank functions.
Despite this, I am getting:
	SongController.h error: 'Song' does not name a type