Gary Allan will headline the Country Throwdown tour hitting outdoor amphitheaters in 20 cities this summer. The tour will launch in Gulfport, Miss., on May 18 and continue through July 8. Justin Moore will appear on the tour's May dates, while Rodney Atkins will join the tour in June. New artists Josh Thompson, Sunny Sweeney and Eric Paslay have also joined the lineup. This is the Country Throwdown tour's third year. Allan's No. 1 hits include "Man to Man," "Tough Little Boys" and "Nothing on but the Radio."