For small town OK, Stillwater isn't that bad. Decent music every now and then. The Red Dirt Rangers come through often. Check them out when you get the chance. Lake Carl Blackwell is kind of nice in the summer. Some of the other smaller lakes are nice, too, since you'll have less boat traffic comming through.
You're also about an hour out of the only two cities in the state. Both get their fair share of music and other things to do.