I found two versions about Coronation in Google. One has 'curururururu' sound, and there's no opening part of the music. Another version has opening part of the music, but there's no 'cururururururu' sound. Which one is really yours? Which one is Civilization 4 official soundtrack? (sorry for my bad english, I'm Korean)
Not sure what the 'curururururu' sound is, but the right one is the one that's on my website, that you get as a free download when you sign up for my mailing list.