The music we call Delta blues is actually a complex interweaving of many regional styles, each with its own distinctive harmonic and rhythmic subtleties. Around Bentonia, Mississippi, on Highway 49, Nehemiah "Skip" James and Jack Owens developed an introspective, gentle music characterized by moaning falsettos and precisely articulated guitar patterns that were conceptualized with a more formalized, systematic approach than the emotionally explosive music that developed in other regions. At 84, Jack Owens is one of the last living purveyors of this distinct regional style. His voice has lost some of its youthful suppleness, but he remains in command of his musical abilities and still provides a thrilling, deeply emotional glimpse into the heart and soul of blues tradition. Owens seldom travels; this is a rare chance to experience one of the most significant musical developments in blues history, in the hands of one of its original creators. Saturday, 8:15 PM, and Sunday, 7:30 PM, 29th Annual University of Chicago Folk Festival, Mandel Hall, University of Chicago, 57th and University; 702-9793 or 702-7300.