CMA Fest (June 11-14) is one of the biggest events in the country music calendar and tickets have been sold out for months. But fans have been given an extra treat with Carrie Underwood being announced as a special guest on the Saturday (June 13). Underwood will be appearing alongside acts such as Jason Aldean, Lady Antebellum and Florida Georgia Line. The performance will mark the tenth anniversary of her first appearence at CMA Fest after winning the fourth season of American Idol in 2005. She shared the news on her Instagram (pictured) by posting a neon-filtered picture of herself wearing â€˜I heart CMA Festâ€™sunglasses with the caption: â€˜Hey #CMAFest! Looks like I will be seeing you real soon!â€™. Underwood is nominated for Best Female Vocalist, Best Music Video and Best Musical Event at the CMA Awards where she is due to make her first post-baby television appearence. Before the CMA Fest Underwood will also take to the Grand Old Opry for two nights (9 and 10 June) and host her official fan club party at the Opry house afterwards. The CMA Fest already has a wonderful line up and Underwood is a brilliant addition that fans will be very exicted about.