What Is Quantizing and How Do I Use It
This article first appeared in FlyPaper by Soundfly. I reprint my original version here, and I encourage you to check out their courses. You can get a 15% discount code on a subscription using the promo code AJTRUMM15.
What is quantizing, you ask? It’s simple on the surface. Quantizing is moving notes recorded into a MIDI sequencer or DAW in line with the “grid”, which makes a rhythmically imprecise performance perfect.
That sounds easy enough, but let’s dive a little deeper so we fully understand what this “grid” is, what quantization really does, and when it might be useful. Ok…deep breath….here we go!
Human Timing, BPM, and The Grid
It may not surprise you to learn that human timing is not perfectly uniform. If a drummer decides to play at a “medium” tempo, that’s a pretty arbitrary idea. Your “medium” could be my “way too fast”.
So, in production, we assign numerical values to tempo. 120 BPM means there will be 120 beats over the course of a minute. A beat here is defined as one quarter note. This numerical definition of tempo allows us to talk to computers about it, and to standardize our own definitions. BPM gives us exact timing for all note divisions.
Those precise divisions make up the “grid”. The grid is not arbitrary. At a given BPM, quarter notes, eighth notes, sixteenth notes – every note you can think of – lands exactly on a mathematically defined place in time. For example, at 120 BPM, a quarter note is precisely .5 seconds long.
But, even if we have a numerical notion of tempo, a human tempo could fluctuate over the course of a song (often desirable). Even if it doesn’t, a human will not hit notes exactly on those mathematically defined divisions.
This is sometimes great, if the player is great and the timing feels great, and everything is just great great great. Other times it’s bad. Say if a player is just off or inexperienced. More importantly, editing arbitrary rhythm that’s not “locked” to the grid can be tricky at best.
Although most DAWs now have the ability to quantize actual audio, quantization is first and foremost a MIDI function, so that’s what we’ll talk about here. However, most of the concepts apply when quantizing audio.
Let’s say you play a simple drum beat with kick and snare into your MIDI sequencer while listening to a click track. When you play it back, you notice that the snare just doesn’t hit right in a couple of spots. Or perhaps you’ve laid down a piano groove or a bassline, but some notes aren’t quite right.
You could move each note manually, using a variety of methods we won’t discuss here, or you could apply quantization to the whole phrase.
Your notes are now magically aligned to the grid and your rhythm track is perfect. Boom, end of article!
Well not so fast. The fact is quantizing could hurt the track more than it helps at times. There are several ways this can happen. Way one is using the wrong quantization resolution.
Quantize To…Or Quantize Resolution
Quantize resolution tells the computer how fine the grid should be. For example, if you pick 8th note resolution, that means all notes will be moved to the nearest 8th note position. If you happen to have played a rhythm that includes 16th notes, your phrase will get changed in a way you didn’t intend.
If you use too fine a measurement, notes could be moved to the wrong grid space, changing the feel of the phrase or ruining it all together.
A good rule of thumb is to quantize to the shortest note you’ve played. If the phrase is all 8th and quarter notes, use 8th note resolution. If you have 16th notes in the phrase, use 16th note resolution. And so on.
Keep in mind that many rhythms might actually use triplets, so you might try using a triplet resolution if things aren’t coming out right.
Once you’ve got your resolution right, you may still notice the track sounding a little stiff and inhuman. If this is the case, you can play with “strength”.
Quantize Strength (or Amount)
Quantize strength works like this. At 100%, it will move the notes exactly to the nearest grid point. To keep a more human feel, you can use strength to simply move notes closer to the nearest grid point, but not all the way there. For example, if a note is ahead of the beat by 60 ticks, 50% strength would move the note back 30 ticks – half of the way home. This can help keep some of that human feel, while tightening the groove.
Another way to humanize a groove is to apply some swing. When a player swings a beat, they’re making the first note of a pair a little longer (or shorter) than the second. Swing distorts the grid so that each pair of notes is unevenly spaced. At 50%, no swing is applied. At 66%, the first note of the pair is twice as long as the second, and at 33%, the second note is twice as long.
Swing can also be a great way to change the entire feel of a track by swinging a previously straight beat.
To this point, we’ve been talking about quantizing to a perfectly even grid, that doesn’t fluctuate. What if you’d like to quantize to a grid created by, say, a live, wild drum track? (Note: “wild” here means not played to a click or other tempo reference – not crazy and awesome).
Groove quantize allows you to quantize to a human groove, or a groove predetermined by software presets. This is particularly handy if you want to lock the grid to a live performance to make editing easier.
Groove quantize works the same as regular quantization, except the grid is defined by the groove source. You may still have to play with resolution, strength and even swing to keep the quantized parts faithful and dynamic.
When, Why and Why Not
Quantization is a crucial tool for keeping productions tight and clean, but it’s not always appropriate. Here are a few times you’ll want to quantize and some you may not:
- MIDI tracks that need to be copied and pasted. The first note MUST be placed exactly on the one, or you’re in for a world of hurt when you try to paste a phrase to another measure.
- When tracks need to be super even and tight – such as in EDM or dance music. A quarter note kick drum, for example, really doesn’t do its job un-quantized.
- To tighten up a drum track, bass line, piano, or anything that forms the foundation of a song. Use strength settings to keep things from sounding mechanical.
Not To Quantize:
- Any time quantization ruins the feel of a part. Undo!
- If a part already sounds fantastic. Don’t fix what’s not broken.
- Parts, such as lead lines, which have a unique human character. Character is often about subtle rhythmic “imperfections”.
- Michael Jackson’s beatboxing. Never, ever, quantize the gloved one.
- Tight live ensembles – unless using groove quantize to adjust overdubs to the original group’s timing.
Lock It Down
There you have it. A quick look at quantization, and how you might use it to better your productions. Quantize is an essential part of an audio/MIDI toolbox, and it can work wonders and make your life easier. But like anything, it’s not for every situation. Use it judiciously, and most of all, use your ears.
Here’s to keeping the beat.