Miranda Lambert is on voice rest this weekend and has canceled Friday's (July 6) appearance at a festival in Varysburg, N.Y., and a Saturday concert in Scranton, Pa. Noting the singer was placed on voice rest because of "overextending her voice," a spokesperson added, "She's under the care of her doctor, and she hopes to return to the road next weekend." Organizers for the Jam in the Valley music festival added Gretchen Wilson and Sawyer Brown to the lineup following Lambert's cancellation. Saturday's concert at the Toyota Pavilion at Montage Mountain in Scranton is being rescheduled. Lambert is scheduled to resume her tour with a Thursday (July 12) stop in Orange Beach, Ala., followed by shows in Atlanta and Birmingham, Ala.