Willie Nelson will join Bob Dylan for a 22-city ballpark tour later this summer. The tour will launch on Aug. 6 in Cooperstown, N.Y., at Doubleday Field and will finish on Sept. 4 in Kansas City, Kan., at Community America Ball Park. All venues will be minor league baseball parks. The Austin group Hot Club of Cowtown will open the show. Nelson also will play Merle Haggard's UFO Music Fest in Roswell, N.M., on July 3 and then host his annual Fourth of July Picnic in Fort Worth, Texas.