We just got these record postcards in at work. Some lady had cases and cases of them in her attic. They're leftovers from the 1962 Seattle World's Fair. Each one has a really bad song on it. You can hear a sample by clicking on the link. I love stuff like this, old boxes of interesting stuff hidden in attics.
I couldn't find any info on google about them. They're really rare. Especially in playable condition.