If people didn’t know about FM, this was a good way to explain it: color vs. black and white. The ad looks ahead to the marvelous post-war future, when everyone will be home from the war, listening to a radio whose exterior looks back to pre-war styles, but whose innards are stuffed with atom-powered vacuum tubes. It would take a while before it caught on, since there was the usual problem: no stations. But there will be more stations broadcating in FM when more people buy the radios! But they won’t buy the radios because there’s nothing on, and it’s too expensive. Yes, but once the price comes down, they’ll buy more radios! True, but the price won’t come down until more people buy them. And so on. Heard that one before?

They probably had the same problem transitioning from the Stone to the Bronze Age. Somehow it all worked out, and the promise of pristine Jeanette MacDonald songs led to 70s rock stations that played the entire side of a Seatrain album so the DJ could smoke a number out back and use the bathroom without rushing, because that harshed his mellow something strong, man.

(National Geographic, 1945)