The congenial, if limited, Burg allows for a solid but not spectacular production. Jason Foreman’s scenic design effectively establishes locations as the Joads travel westward from near Sallisaw to California. Some stage trapdoors reveal campfires, Grampa Joad’s grave, the Colorado River and other settings. The excellent musician Sonny Franks serves as narrator and “troubadour.” He fills in the story line, provides incidental music and sings period songs and hymns while playing various stringed instruments. The cast does a fine job for the most part. This modest production depends so much on the actors’ performances. Cameron Cobb makes a likeable Tom Joad, newly paroled from prison in McAlester. Cobb effectively captures Tom’s hotheadedness