2013 Grand National to modifications made for the previous year's race, Aintree announced that a number of further changes had been made for the 2013 National. Twelve of the 16 fences on the course were rebuilt with the timber frames within them replaced by a softer material known as "plastic birch". The fences are still covered with at least 14 inches of spruce and will remain the same height. The starting line was also moved 90 yards closer to the first fence, further away from the spectators' stands and thereby reducing slightly the overall distance. Aintree and the Professional Jockeys' Association jointly issued
The Times They Are a-Changin' (song) be last, and the last first." Less than a month after Dylan recorded the song, President Kennedy was assassinated in Dallas, Texas, on November 22, 1963. The next night, Dylan opened a concert with "The Times They Are a-Changin; he told biographer Anthony Scaduto, "I thought, 'Wow, how can I open with that song? I'll get rocks thrown at me.' But I had to sing it, my whole concert takes off from there. I know I had no understanding of anything. Something had just gone haywire in the country and they were applauding the song. And I couldn't understand why