[QUOTE=Derleth]
These days, whenever two different ways to deliver the same content are invented at the same time, we expect them to duke it out for Total Market Supremacy. VHS vs. Betamax, Super Audio CD vs. DVD Audio, Blu-ray vs. HD-DVD. There Can Be Only One.
This, of course, explains perfectly why 10 inch gramophone records came in 33⅓, 45, and 78 rpm forms for quite a long time.
No. Wait. That non sequitur is a crack monkey on wheels.
What was the deal?
[/QUOTE]
Mostly the deal was that:
78rpm was an older format. When “data compression” improved, such that smaller grooves with smaller wiggles in them could convey the information satisfactorily, 78s became obsolete, but there were enough of them around that plenty of record players still supported them. Mostly these were 10" discs.
45rpm with the smaller grooves provided enough playing time on a 7" disc to record a single track of up to about five minutes, and there was a thriving market for singles - heck, it was a major part of teen culture from the 1950s onwards. (Although not to me, but then I was odd.)
33⅓rpm with the smaller grooves on a 12" disc provided enough playing time to record six to eight tracks a side, enough for a respectable-sized album.
Our Dansette radiogram also allowed for 16rpm playback, which I believe was for speech-only recordings, but I never saw one.
It seems hard to believe now that it felt like vinyl records had been around for ever, and would continue to be so.