In a video message to fans, Sugarland's Jennifer Nettles addressed her voice problems that resulted in the cancellation of two shows in California over the weekend. Nettles said she's been having problems since January and that the combination of singing in the studio and being on the road sidetracked her. "I sang too much. And I blew my voice," she said in the message posted Monday (July 20) on Sugarland's official Web site. "It's like a muscle. It's like any other part of your body. If you sprain it or strain it, then you have to heal it, or else you will break it. And I don't want to break it. I want us to come back out there and see you." Sugarland canceled their appearance at Kenny Chesney's stadium show in San Francisco on Saturday (July 18) and Keith Urban's arena show in Los Angeles on Sunday (July 19). Nettles was previously placed on a 10-day vocal rest in May 2009. They also canceled three dates in September 2008 due to Nettles' throat and sinus issues.