Former American Idol runner-up Lauren Alaina has been placed on doctor-ordered vocal rest and has canceled her weekend concerts with Sugarland. Singer Vonda Shepard, who had a recurring role on the Ally McBeal television series, will fill the opening slot on Sugarland's shows Friday (Aug. 3) in Cincinnati and Saturday in Clarkston, Mich. "I am so sad that I have to miss this weekend's shows in Cincinnati and Detroit with Sugarland," Alaina said in a written statement. My doctor is putting me on vocal rest. I'm really sorry to disappoint the fans who were coming to see me and my friends Sugarland, who have helped me out on their tour. I will make it up to you and be back soon."