All you Blues fans in the midwest should look into the Madison (IN) "Ribber Fest" coming up in August.

It's a great time with top name Blues bands, hot air balloon races and BBQ cook offs on a State level.
Camping is available at Clifty Falls State Park (Madison) and , if you're lucky, the city camp ground might still have some sites.
It's been a tradition with me for the last six years and I look forward to it every time.

Let me know if you need more info.