December 1975: "Chicago IX: Chicago's Greatest Hits" Rules the Holidays Packed with fan favorites like "25 or 6 to 4" and "Colour My World," the album spent more than a month at the top spot. What's the greatest of Chicago's greatest hits? Tags Chicago Chicago IX Chicago's Greatest Hits Read more about December 1975: "Chicago IX: Chicago's Greatest Hits" Rules the HolidaysLog in to post comments