Thursday on Eight Forty-Eight we look at the blues: Sitting in for host Tony Sarabia, WBEZ’s Richard Steele plays tracks from Blues Fest’s lesser-known artists and chats with David Whiteis, author of Chicago Blues: Portraits and Stories. Celebrated Chicago bluesman Billy Branch also joins for a performance and talks about how the blues – and who plays it – has changed in his lifetime. To join the conversation, call 312.923.9239.