My wife and I went last fall; I'd been several times before. One night we went down to Broadway for a bit--it's best to go early, our friends said, because the clubs there get overrun wth bachelorette parties (note: this might be a good thing for the single guys). As was said above, the bands play for tips, thus there's no cover, and the bands are pretty killer. We spent most of our time at Robert's Western World, which is both a music venue and a clothing store. Fun place.
After an hour or two, we headed over to the Station Inn, which is known for hosting bluegrass acts. Totally different vibe than Broadway, very laid back. The band we saw there was really great.
As for food, if you're up for hot chicken, Hattie B's was strongly recommended to us, and it didn't disappoint. We went there close to noon on a Sunday and got hot chicken and waffles. It was quite good, and so filling that I didn't eat again until I basically made myself eat a sandwich at 9 pm on the plane home.
Also, if you get a chance, catch Doyle and Debbie--their act is hilarious. They typically perform at the Station Inn.
The Doyle And Debbie Show