'The Gospel According To Nikki Giovanni' reimagines hymns; History of the book index

Renowned poet Nikki Giovanni and saxophonist Javon Jackson speak with correspondent Tonya Mosley about their new album, "The Gospel According to Nikki Giovanni." And, Dennis Duncan's new book, "Index, a History of the: A Bookish Adventure from Medieval Manuscripts to the Digital Age," explores the development of those things in the back of a book that many of us turn to for reference.