Just looked at American from Nashville to Zurich round trip 9/1-9/17 and it was $839.26 and would let me book it. Don't know if they have it posted wrong or what as the norm is about $1300. So if interested look now and may get a deal on Europe.
Not sure how many Travel Forum folks are searching for good fares from Nashville to Zurich for the dates listed, but the idea that good fares can be found on occasion is confirmed by some of my past purchases.
For that price, you should have grabbed it. I see it now @ $1440. The cheapest you can make that route is through Toronto for $1232--Per ITA Matrix.
More deals available here...