I don't know why, but for some reason I started thinking about 33 and 1/3 RPM as the standard speed for LP phonographs. I think about weird things sometimes. Maybe it was the 33.3 reading on our fancy indoor/outdoor digital thermometer.

(And why the compelling need for a "point" something reading on an indoor/outdoor thermometer anyway? Or for that matter, on scales for weighing yourself. Does "point" two or "point" five really communicate any additional meaning about your weight or the temperature outside? My theory is that it's a marketing gimmick to give the "appearance of precision" that people respond to for some reason. But I digress.)

Read more after the jump...

If you think about it, 33 and 1/3 RMP is a great number for playing music. In the digital world, it isn't even really a number. It's more of a concept, or an approximation. It can't be expressed in binary. Or decimal. Just divide 1 by 3 on your calculator to see what I mean. It just goes on and on in an infinite string of threes.

But in the analog, electromechanical (i.e. "real") world, it's a simple function of using the right gear ratios and input voltage to get pretty close to precisely 33 and 1/3 RPM.

That's what makes it perfect, numerologically speaking, for music, which isn't perfect at all. Variations in the materials instruments are made of, ambient temperature and humidity, and all sorts of weird things, not to mention playing technique, affect the sound we eventually hear. And, for most of us anyway, our ears aren't perfect, or exactly alike. So each of us hears something slightly different, and we process what we hear in our own unique, individual ways, applying our own psychological and cultural filters. Which accounts for different tastes in music.

Using a pseudo-scientific analogy (because I'm no scientist), analog 33 and 1/3 is sort of like a sine wave, as compared to digital, which is more like a square wave. With a smooth, analog sine wave, there are an infinite number of frequencies, and an infinite number of variations between the frequencies. With a square wave you can have all the frequencies you want, but the steps between frequencies are limited by the number and precision of the multipliers, sort of like stair steps in between. With enough steps, you can "smooth out" the wave and make it look or sound like a smooth sine wave from a distance.

In the digital world, this is exploited (along with the limits of human perception) to make lots and lots of ones and zeros and the steps in between give the appearance of smooth transitions and relationships between tones and sound levels in music (or shades of color and light intensity in a photograph). It's an almost perfect approximation, within the limits of human perception anyway. But it's all just an illusion.

My old ears can't tell the difference, except that a digital CD or MP3 "sounds better" because it has more dynamic range and doesn't have all the pops and hiss and wow and flutter of a vinyl LP. But some purists insist that analog gear like tube amps and magnetic tape recorders and vinyl records give a "smoother" or "warmer" sound, and insist on using such gear in the studio or their home theaters.

While that may be technically correct from a sort of sine wave point of view, and some people may actually be able to hear it, I'm not a purist in that sense and like the convenience of digital media. And besides, when digital came along all of the research and development went in that direction as analog fell mostly by the wayside, leaving it sort of frozen in time.

But there are things I miss. I miss the little built-in strobe on turntables that let you dial in the RPM to compensate for fluctuations in power or drive belt wear and so forth. I also miss the old four-speed turntables that would let you play a 33 and 1/3 LP at 16 so you could hear it at half speed, which came in handy for our circa 1971 sock hop band to pick out and transcribe complicated Chicago and Blood Sweat and Tears horn parts.

But mostly, I think the world is an analog place and real life happens at 33 and 1/3. There's no real precision, and there are infinite variations and nuances in everything we see, hear, and feel. There are an infinite number of notes between C and D, and there are an infinite number of colors between any two shades of "blue". Maybe every now and then we should take the time to look closer between the frequencies for truth and meaning.

OK, then.

P.S. Here's and interesting technical/engineering discussion [1] of how 33 and 1/3 RPM came about. As with many standards in sound and photography, you can credit (or blame, depending on your point of view) the motion picture industry.