I wouldn't be CITY OF NEW ORLEANS, Steve Goodman wrot that in the '70s, Check with SMITHSONIAN FOLKWAYS as they have all the stuff Woody recorded(even some of the non-coommercial stuff). It could have been NEW LOST TRAIN BLUES that Woody recorded with Alan Lomax for the LofC. I seem to recall that Lomax committed what was then cardinal sin of injecting himself into the interview, instead of maintaining what was then considered to be a folklorists proper objectivity.

Mark Ross