Halloween is almost upon us. What better way to unleash your inner beast than attending Chicago's greatest fall music festival. Come out and rage in your festive costumes with over 70 artist's performing. With headliners such as Bassnectar, Armin Van Buuren, Pretty Lights and Carnage you certainly won't be disappointed. Once all of the chaos subsides from this wonderful event there are great official after shows in the city. Check out the line up, official video and afterparties below.