MIDI Quantization: The Best MIDI Editing Feature of them All

Whether you are a new or accomplished musician, learning how to work with MIDI is essential. GW Childs explains the basics of MIDI Quantisation and how to tighten by the timing on your recordings.  

In my last article on MIDI, I filled you in on what MIDI is, isn’t and how it can benefit you. In this followup article, I’d like to show you a feature found in most every DAW, but especially Garageband, that can make your MIDI life much, much better.

This particular feature, as the title above gives away, is known as Quantization. And, if you’re getting in to music production on a computer... You really need to know about it.

[Ed- For a really in depth, informative and entertaining tutorial on MIDI, check out the MIDI 101 - MIDI Demystified Tutorial Video.]

As I mentioned in the last article, when Garageband, or any other DAW records you playing a MIDI instrument, it’s not recording you in the classical sense. It’s only recording your key-presses, not the sound coming from the MIDI instrument itself. I also mentioned that this is incredibly cool, because you’re able to go back and edit the timing, placement, key, etc of particular notes you’ve played. 

This can get extremely tedious though. Think about it: A couple of measures worth of notes can add up to somewhere between 16-32 notes, and that’s if you’re a really basic player. Do you really want to go back and have to correct every little note you’ve played? Well, some do. Those tend to be either the types that want complete control in every aspect of production, or players that are just soooo good, that they have very few edits. 

The rest of us just want to get our song done quick, and sounding good, right?

Enter quantization! To quantize means to actually have the computer move particular notes over to the nearest note value based on the criteria you’ve assigned.  Or, in real people speak- It tightens your playing up!

Let’s explore quantization together here in Garageband. I have this piano part that isn’t necessarily bad... It’s just a little choppy. Let’s see how quantization can quickly fix this!

Step 1 - Double Click Your Recorded Region

When you record MIDI in Garageband, the recorded part appears as a small colorful region with little dots in the middle of it. The dots, of course, represent notes you’ve played. 

When you double-click on a recorded region, you open up the Piano roll editor at the bottom of the Garageband interface.


Step 2 - Enable Quantize Note Timing in Piano Roll

If you look closely at the notes that I’ve played, you’ll notice that they are inside a grid. 

The grid lines indicate proper timing, as the computer sees it. The notes, themselves, are sometimes within the grid lines, sometimes not. This is MY timing. When you play back the recorded part with my timing, it can sound good sometimes... and very bad sometimes. If I use my mouse to move over notes that are not lined up in the grid, this will fix MY timing. Though, as I mentioned earlier, having to move every note to it’s proper place in time can be an exercise in patience.

Here’s where it gets fun... Turn on 'Quantize Note Timing' over in the left hand corner of the piano roll. Notice how all of my notes are exactly on the grid lines now... Cool, eh? Let’s hear it too!

I’ve set my timing to 1/8th note, because I’m actually playing in 8th notes. I know this... But, if you’re not sure about your timing, just choose some settings and see what works. The most common settings are 8th and 16th. These are good starting places, but I always recommend experimenting. Quantization can even give you new ideas!


Now, you may notice that it sounds a little too tight, in some cases. This is where quantization can take a little of the humanity out of your music. In the next tutorial, I’m going to talk to you about humanising computer recorded MIDI. See you there!

There's so much more to MIDI that most of us think. Take an entertaining journey into the world of MIDI with Logic expert, MIDI maestro and successful composer, Peter Schwartz in MIDI 101 - MIDI Demystified.

Sound Designer, Musician, Author... G.W. Childs has worn many hats. Beginning in the U.S. Army back in 1991, at the age of 18, G.W. began learning electronics, communications and then ultimately audio and video editing from the Department of Defense. Upon leaving the military G.W. went on to work for many exciting companies like Lu... Read More


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