In terms of the song, American Pie is used as a metaphor for the USA. The expression 'Miss American Pie' might sound like it were being used as a sponsored beauty pagent title, but I've always thought that Don McClean was attempting to conjure a (rose-tinted) idea of US greatness, incoporating all sorts of notions of god-fearing, being wholesome, family values type stuff. She's supposed to conjure the US ideal woman (or supposed ideal, at any rate) - the girl next door. The song is known to be about the death of Buddy Holly,and my personal take on it was that it destroyed McClean's view on life - it was his wake up call that things don't always go as planned, you don't always get the girl you want, and heroes let you down. I believe Don McClean has maintained a reasonably dignified silence on the deeper meanings of the song. The movie took its name from the song.