Penny Von Eschen is the author of "Satchmo Blows Up the World." She tells Steve Paulson about the State Department's use of jazz musicians as a weapon in the cold war to win hearts and minds in the Third World. Louis Armstrong, Dizy Gillespie, Duke Ellington and Dave Brubek were among the so-called "jazz ambassadors." And we hear lots of their music, much of it recorded on these tours.