How tall?? Rounded? Upright Arching? Fountain Grass usually refers to Pennesetum grasses. Was it in bloom? Color of blooms? Characteristics you can share? It's hard to help without more info. Pennesetums make a beautiful choice for lining driveways. A note with them is that they will like some water to look their best if they are in full hot summer sun.

I remember that they were very tall, don't remember any blooms and it was upright arching. I thought maybe someone in that area or someone that had visited Nashville might know what I am talking about. Thanks pezhead for the info, I really appreciate it.

If the grasses you saw were upright and arching and quite tall, it sounds like Miscanthus of some kind. Go to a good library and see if you can't find the Color Encyclopedia of Ornamental Grasses by Rick Darke. In it you will find pictures af many grass cultivars and may be able to locate the one you saw in Nashville. Be warned that some Miscanthus cultivars are considered quite invasive in the Southeast.