There are really several bar options in Nashville and I'm not sure exactly what you want to get into so I am going to give you a couple of options to start with.
If you are heading toward downtown Nashville on I40, you would take I40W toward Memphis and get off at the Demonbreun exit. Turn left and you will be at Music Row (this will be opposite side of the interstate from downtown).
Variety of bars in this area. Park in the hotel lot on the left and you can walk up and down the strip across the street. The Tin Roof is probably an alll around safe bet. Will ususally have a live band late night. Other options in that area are Dan McGuinnes- Irish Pub, 2 Doors Down- Sports Bar.
Another option is to head downtown and find a place to park. (Cheapest place to park $3 -is on 7th and Commerce in the Convention Center Garage) From here you can walk over to Broadway and 5th and start hitting some of the honky tonk bars (no cover charges). Worth going to for a few beers just to say you have been. Try Tootsies or Roberts. From there keep walking down Broadway toward 2nd avenue. Turn left and you will have numerous bar choices ranging from your tourist traps Hard Rock Cafe and Hooters to a few off the beaten path like Windows on the Cumberland (Jam bands often play here but Tues. night band is not listed on their website).
For late night, and a little more of a local flare you can head over to East Nashville to a bar called Beyond the Edge.
Go to Nashvillecitysearch.com and you can probably read about lots of these places as well as others. Email me and I will be glad to give you more detailed directions and other suggestions based on what part of town you might be staying in or try to answer any questions about any places you might read about.
Probably a little more info than you actually wanted.. ;D
going to need a place to chill for a few hours while waiting for a ride from nashville airport.. can someone suggest a bar/restaurant in the area off of 40 or 24s that would be easy for an rv to pick me up from.