Lady Antebellum, Jason Aldean and the Zac Brown Band are among the artists booked for Country Thunder festivals in 2011. Aldean, Toby Keith, Martina McBride and Sawyer Brown will headline Arizona Country Thunder, held April 7-10 in Florence, Ariz. In addition, Lady Antebellum, Martina McBride, Rascal Flatts and the Zac Brown Band will perform at Wisconsin Country Thunder, held July 21-24 in Twin Lakes, Wis. Tickets are now available for both festivals. Additional artists will be announced in the coming weeks.