Rock and Roll started out as an interracial forum, but Slate’s pop critic Jack Hamilton says rock turned into a predominantly white music genre, and he’s piecing together why. Also: The history of the great American game of baseball represents all the paradoxes of race relations in our country. Johnny Moore studies the surprising shift from the 1920’s, when baseball held an important place within the black community, to today, where that place lies in the NBA.

Later in the show: The late Julian Bond conducted 51 extensive interviews with prominent black leaders in America. Phyllis Leffler, who led the project with Bond, has written a book on the series that offers insights into the intractable disparities of race in America. Also: In the 1940’s Fatima Massaquoi penned one of the earliest known autobiographies by an African woman. Arthur Abraham is one of three editors of The Autobiography of an African Princess, which traces Fatima’s life from her youth in Africa to her later years in America.