This week on “The Juke Joint” broadcast Robert Barclay celebrated some history of Houston’s Juneteenth Blues Festival. He included music by Johnny Clyde Copeland, Albert Collins, BB King, Bobby Bland, Clarence “Gatemouth” Brown, Lightnin’ Hopkins, Clifton Chenier, Sippie Wallace, Lavelle White, Eddie “Cleanhead” Vinson and Big Mama Thornton, among others.