With a family, an RV would be a good adventure and get you to areas you may not otherwise go to.
V good campgrounds/state parks and you can cook your own food. Nashville not suitable for country music with kids as all bar based music and they won't get in. Best to seek out a bluegrass festival and bring the RV there. Most themeparks also have a campground nearby too.
Have used both ElMonteRv and Cruiseamerica before and good companies to deal with.
Dollywood is a good spot with plenty of music in surrounding areas.