Why is it 33 and 1/3?
Well it is. It says so on an answers website. But it’s not quite the right answer. It’s not enough to imply it was random choice. Kudos to the guy who answered but the answer why was the speed 33 and 1/3 chosen is ok but it doesn’t have the rock bottom fact that is required, so here it is…but first, a question:- Why can you not write fractions on a pc? That really is one thing that needs to be looked at – in many ways, fractions are neater than decimals.
Well anyway, here is why the records were 33 and 1/3. It certainly was not a random choice. I didn’t know at all until I was on a visit to a certain cinema, where I was shown a demonstration of a genuine 1920s Vitaphone machine.
Now don’t get me wrong, I expect if you have come here because you saw the word “Vitaphone” you will know this anyway….just that most people don’t know the word “Vitaphone”, what it was how it worked and so on, so here is my take on what I was told and so after that, you can draw conclusions or you can agree with mine.
Vitaphone was a playback process invented in the 1920s to give us sound movies. Talking Pictures – like the old song “…if I had a talking picture of you….ooooo…”
The thing is that the Vitaphone thingy was a projector and sound disc that had to be played simultaneously; a record played and a film projected from the same machine.
That meant that the machine looked kinda crazy. Like a huge film projector with a record turntable at the bottom.
The mechanism to drive the film and the record turntable simultaneously were co-ordinated mechanically by an electric motor and a chain drive.
To get the speed of the film correct, it had to go through the machine at 24 frames per second. To match the disc exactly to the film, the recording had to move at 33 and 1/3 revolutions per minute. Get it? It was a great invention.
These discs lasted for 11 minutes and were single sided. (Normal records at the time revolved at 78 rpm and lasted about 3 to 4 minutes per side).
The discs were played with an ordinary steel needle – albeit a bit longer than those for a normal record player of the time.
The skill of the operator was to get the disc married exactly to the correct part of the film. This was somewhat difficult.
From the projection room, high above the auditorium, the sound of the disc was picked up by a telephone microphone. This sound was then carried over wires to the side of the stage where telephone earpiece receivers were placed in wooden acoustic exponential horns. In other words, the sound was magnified acoustically.
In some big cinemas from the 1920s and 1930s, you can also see acoustic domes from those days (if you know where to look). Those domes were meant to magnifiy the sound of the film for the patrons who were sitting in acoustical dead-spots.
All very clever really.
How it became the norm for Long Playing records was brought about because the technology was there. It was invented as part of the Vitaphone process. They fixed the speed of Longer playing records at 33 and 1/3…of course, the technology was soon superseded by other ways of getting sound on film…the cumbersome vitaphone process was forgotten…but its legacy is still very much alive…
If you ever get a chance to see the Vitaphone machine at work, take it. It is fascinatiing.
Vitaphone gave us some talking pictures but also gave us the means of long playing records….
Of course there were others involved and the real development for long playing records took place after the Second World War, I believe it was the Columbia company who did this but then, I may be wrong…
So remember, when anybody says why is it 33 and 1/3rpm, the answer is because the speed was fixed by the Vitaphone company for the first talking pictures: 24 frames per second required the disc to revolve at 33 1/3 revolutions per minute…which meant that a disc lasting 11 minutes had to co-ordinate simultaneously with the film…
Visit the Plaza!
Wonderful isn’t it…Now who was it who said on Vitaphone “You ain’t heard nothing yet!“?.
You bet they said it at 33 and 1/3rpm!