It was only a day trip we made to Nashville, but there was time for a bit more viewing than just the Parthenon. Pretty much as a shot in the dark, and armed only with sketchy guidebook on the iPad, we opted to go to the Frist Center for the Visual Arts. It turned out to be a very lucky choice (and not only because it had a rather nice caff attached).
The Frist has been converted out of what was the old main post office in town -- one of the grandest and most distinguished post office, you could ever hope to enter, in the finest and most extravagant art deco style.
And with the most wonderful details and vistas (this photo of the stair well by Jay Farkas).