In American society, it is widely acknowledged that white people should not say the n-word. Nor should they rap it. Nor should they rap it on stage at a Kendrick Lamar performance in front of thousands of people. One white-appearing woman, identified in a video as "Delaney," learned that lesson the very public way at Alabama's Hangout Festival on Sunday. Lamar invited Delaney onstage during his song "M.A.A.D. City," which chronicles the rapper and recent Pulitzer Prize winner's experiences growing up in Compton. The song contains 15 instances of the slang word "n---a," three of which Delaney rapped with abandon....