However, I find the ad itself to be a little offensive: comparing first-world problems of a couple of affluent yuppies with people eking out a living in a mill under the worst of work conditions (No OSHA in those days). If Pete hadn't been cremated, he'd probably be spinning in his grave.
I wonder if Pete's estate agreed to allow this song to be used? Maybe no permission was needed. This was a Folkways recording, and the Smithsonian now owns the Folkways catalog. Since the Smithsonian is a quasi-governmental agency, it may not be allowed to withhold permission to use Folkways material.