William Grant Still Arts Center recognizes first black record producer and musical pacesetter in February exhibition Contact Joyce Maddox 213-847-1540 LOS ANGELES -- JazzGenesis: Benjamin Franklin "Reb" Spikes and the Central Avenue Jazz Scene, 1919 to 1945 unveils the obscured legacy of a musician who helped open the doors to the entertainment industry for blacks in Los Angeles. The exhibition begins Jan. 29, 2005 with a panel of recording industry executives discussing the future of