Quantizing MIDI in Reaper is insanely easy. Not that its particullarly difficult in other DAWs, but its just really quick in Reaper. Before we get going with this tutorial, we’re going to assume a few things:

1. “Grid” is turned off in the Piano Roll
2. “Snap” is also turned off in Piano Roll
3. Grid can either be on or off in the Arrange window

So first, create a new track and insert a MIDI event (Insert -> New MIDI Item). I created a two bar loop, you can make a loop of whatever length. Create a bunch of MIDI notes. Once you’ve created said MIDI notes, double click on the MIDI region to open up your MIDI Editor. The notes will be un-quantized (unless you have Grid and Snap on), and we’re going to fix that.

The next step is, inside the MIDI Editor, go to Edit -> Quantize events… or just hit Q on your keyboard. You’ll be brough to this menu which is pretty much the same in all DAWs:

MIDI Editor Quantize menu

This is the asy part.

• Either click “All Events” or select the notes you want to Quantize and hit “Selected Events.” For this purpose, I’m using “All”
• “Quantize Positions” will affect the left-to-right aspect of your notes: you’ll probably want this checked. You can also change the note value (1/4, 1/8, etc) and allow Reaper to take the off-note items and put them on with the rest of your MIDI. You may or may not want this, so try it out.
• “Quantize Lengths” will affects your note durations. Checking “Allow shrink” will let Reaper shrink notes it thinks it should, while “Allow grow” will give Reaper permission to make notes longer. Again, you can change the note value here.
• “Strength” can be pretty important. This tells Reaper how hard you want it to quantize your notes. 100% will be 100% quantized; that being every note will be exactly on the grid. It’ll sound like a robot playing drums, which, if you’re doing any type of electronic music, you probably want. However, if you’re quantizing a live instrument like acoustic drums or percussion, you may want to experiment with this a little bit. Laying off the strength will give the performance a more natural feel.
• “Swing” will dictate how often your notes deviate from the quantization scheme you’ve set up. Again, for electronic music, you probably want to leave this at 0%.
• “Quantize within” isn’t that cryptic at all. Set at what you see in the screenshot, it will quantize 100% of your notes. Set from 60-100%, it’ll quantize 60-100% of your notes. (If I’m wrong about this, and I may be, please correct me in the comments).

After all your settings are just how you like them, hit “OK.” Bam! Your notes are quantized!

Before...

After!

That’s all there is to it. Leave me a comment, hit me up on Twitter or Blip.fm, or just send us an email!

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