Blake Shelton has joined George Strait's summer tour as the middle act. Their first show together will be May 15 in Charlotte, N.C., with concerts scheduled through the end of July. As previously announced, Julianne Hough will open the shows. "I have the utmost respect for George Strait, and to be invited to be on his tour is a huge honor," Shelton said. "He truly is a living legend. Thank you, George Strait, for this incredible opportunity."