Dr. Martin Luther King, Jr. is often regarded as a brilliant orator and a champion of nonviolence, and his speeches -- especially his "I Have A Dream" speech -- is endlessly quoted by politicians and activists. But what of the Dr. King who spoke out against the Vietnam War, against police brutality and against economic injustice? This is the lesser-known King -- the scholar, author and radical philosopher who is the subject of two new books by local scholars. We speak with these scholars about the real King and his legacy 50 years after his assassination. Guests: Brandon Terry, Harvard University; and Jason Sokol, of the University of New Hampshire. In this week's Lagniappe segment: It was Martin Luther King Jr.'s favorite song: a hymn called "Take My Hand, Precious Lord." He often requested it to be performed at rallies and demonstrations, and on April 4, 1968, a request for this song turned out to be his last words. We explore the significance of the song in Dr. King's life and in the civil rights movement. Guests: Ingrid Monson, of Harvard University; and Dennis Montgomery III, of Berklee College of Music. More UTR: news.wgbh.org/UTR Like us on Facebook: facebook.com/UnderTheRadarWGBH Follow Callie on Twitter: @aasuaje