It's odd that even when cruising at 20,000 feet, heading north from New Orleans to the Chicago Jazz Fest, there is a sense of history to this route taken by so many of our musicians. They, of course, mainly went by train, car, boat and bus, but nonetheless, when looking down to the winding Mississippi below, the spirit of those musicians lingers—Jelly Roll Morton, Freddie Keppard, King Oliver, Sidney Bechet, Johnny and Baby Dodds, Louis Armstrong, and so many more. From around 1910, the strea...