When I was a little kid I remember seeing lots of turntables that had speed-settings for 78, 45, 33 1/3, and 16 2/3. I remember asking about the lowest speed, but no one seemed to know what it was for, and I also never saw record for that speed. Since then, I've heard that it was for spoken-word analog discs, but they must have been uncommon, at least by the mid-60's.
I was going to mention mini-(CD)discs, but several people beat me to it. As I recall, part of the reason that the format died quickly in the US was suspicion on the part of the consumer. A lot of people, myself included, were mighty leery of a new format being foisted on them by the recording industry barely 10 years after the introduction of the CD.
As for 50's reel-to-reel, Art Pepper recorded some excellent material for "Omega-tape."