All He Had to Do Was 'Dream'

Op-ed at NYT by author of book on MLK's "I Have a Dream" speech 50 years ago--explaining how the "dream" thing was "improvised," with a little help from....Mahalia Jackson.   He had only five minutes for the speech and decided to cut a few things at the end and add that little thing.  As we know, the Wash Post didn't even mention it.