Bullet to your point about musical associations- I agree that different songs do evoke different meanings among different folks and heaven knows I've been in enough good times where people blare the refrain "Born in the USA" and that's the association. I personally like Springsteen's music.
And yet - the lyrics aren't really all that opaque in Born in the USA and really you don't have to have a degree in comparative music to see that it's not exactly a celebratory song that really brings out what the 4th is all about for most folks. Lyrics do matter - at least to me, and I personally just wouldn't associate that song as a July 4th tune any more than I would suggest listening to Country Joe and the Fish on Veterans Day
http://www.youtube.com/watch?v=xuUBCF3KKxc. But you know- it's a personal deal- there is no right and wrong to these kind of conversations and there isn't supposed to be.
Musical association is pretty powerful- I often find that songs bring back really strong, intense memories of either where you were when you first heard it played, or what you were listening to when something really memorable occured. When MTV came out- I hated the whole concept because I thought that it essentially manufactured associations rather than leaving you with a memory that you created yourself (And I guess I wasn't alone because the original premise of MTV has essentially died). Some songs are always gonna stay associated with unique events for all of us- and at least for me, I'm transported back in time to that event when I hear them. It's one of the really nice things about music. Of course it drives my wife and daughter crazy because when listening to XM Satellite radio in the car we always seem to be on Channels 60's on 6 or 70s on 7. Their associations with those tunes are probably mostly intense boredom
Bottom line- this is supposed to be a general "sitting at the bar having a beer shooting the bull" type conversation so let's make sure that nobody takes any of this personally- it's the ultimate "nobody's opinion is more or less valid than the next" topic