What is quantization?

For musicians who work in recording or producing realm, quantization is an issue that comes up frequently. As for me, I deal with it on some level in almost every recording project I create.

So what is quantization anyway? Well, the long answer is “It depends on who you ask”.

• An online dictionary will tell you:
  The process of converting, or digitizing, the almost infinitely variable amplitude of an analog waveform to one of a finite series of discrete levels.
• Audio-technicians might tell you:
  Quantization is the process of converting a continuous analog audio signal to a digital signal with discrete numerical values. Example: In a compact disc, an analog recording is converted to a digital signal sampled at 44,100Hz and quantized with 16-bits of data per sample.
• A physicist will tell you:
  To apply quantum mechanics or the quantum theory to something.

However, for a recording artist or musician, the meaning of quantization is a little bit different. I define it as: “Making music mathematically perfect.”

In other words, when a person plays a keyboard, drums, bass, sax, etc. into a recording device, the recorded performance usually lacks precision in timing to some degree. Although it may sound good, each note is likely not placed exactly in the correct spot in time. To record something with absolute mathematical precision would be nearly impossible for any human.

Enter Computers. So to compensate for the lack of timing precision, computers can come along behind us and make sure all of our timing is adjusted, lined up, and perfect. This is the act of quantizing.

Quantizing is done very easily when working with MIDI note data. Since MIDI notes each have a definite start and end time, all the computer has to do is recalculate the note data so that each note starts at the correct time and presto, you have perfect timing.

However, the process is not so straight forward when working with non-MIDI audio (voice, guitar, etc). When there is not a precise start time to the note, it is more difficult for quantizing software to know where to put each note in time. Waveform quantizing software has to basically guess where the individual notes are. As technology gets better, these programs are getting more and more accurate, but there is still some element of guesswork when trying to quantize waveforms.

The Quantizing Challenge

Nearly every recording software available today has a quantizing option built in and a ton of settings to go with it. The problem that many people fall into is that they think quantization will fix their timing problems in general. But let me be honest, if you can’t play with the beat at least to a pretty decent level of accuracy, don’t think the quantize button is going to fix it. For Quantize to work, you have to get the notes at least CLOSE to where they go in the timeline.

Most of the time you can choose if you want the computer to quantize the notes immediately as you’re recording, or later when you go back to edit. But either way you are going to tell the software you want to snap the notes to the nearest 8^th note (1/16 note, 1/2 note, etc.), so you have to be a good enough player to be able to place the notes pretty close to the correct time. If you are too sloppy, you’ll have notes shifting to the wrong places and the final product will sound horrible.

The Quantizing Catch – Should we?

Now that we are on the same page as to what quantizing is and how to do it, the big question on everyone’s mind is “Should we even do it in the first place?” First you go through and play in your parts, and then go back and correct all your timing mistakes with quantization. After all, it does seem a little like cheating, doesn’t it? That actually is a very good question… “Should we?”

I think it comes down to personal taste and style. Computer music done for the electronica scene will not doubt be heavily quantized. In fact often the programs used for this genre don’t even give an option to shut off quantize. Country, blues, gospel, opera or classical would be expected not to use this timing correction process, but I’m sure many do.

I remember hearing a Bruce Hornsby song where there was an orchestra and of course a piano part over the top of what sounded like a very synthetic drum track. In that case, I would assume the drums were heavily quantized and the rest was probably not. But who knows.

Personally, I don’t mind the rhythm tracks (bass, drums, etc.) to be mathematically perfect, but I prefer the humanness of the main instruments. The slight timing nuances of the players gives the music more life for me. That why I prefer live music to recordings anyway. But being a computer music buff, I also appreciate the heavily quantized sounds of the industrial music scene as well.

Tell me what you think. Do you have any quantizing tips, tricks, or stories? What do you think sounds best?