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The Basics of MIDI Quantizing
If you have spent any time around DAWs or MIDI sequencers I am sure you have come across the term “quantize” at some point or another. You may have heard the term referenced with phrases like, “it strips away the feel” or “makes music sound robotic.” Quantization has gotten a bad rap over the years, often because people don’t understand how to implement it effectively. If used correctly, quantizing can actually be quite musical and is an indispensable part of the sequencing process, especially if (like me) your performance skills are less then perfect. On that note, I would like to dedicate this weeks Pro Tools corner to a primer in MIDI quantizing within Pro Tools.
Quan-what?
Essentially MIDI sequences in Pro Tools are just a series of note events that take place at some location relative to the bar beat grid, sort of like digital sheet music. MIDI can contain information about pitch, timing, velocity, and various controller parameters that relate to the performance or instrument. Because MIDI data is not converted into audio until it gets passed to a virtual (or hardware) instrument by the sequencer, the possibilities for manipulation are virtually limitless. This is where quantizing comes in.
Quantizing allows you to take a selection of MIDI notes and automatically modify their timing relationship against the bar/beat grid, based on a set of user-inputted parameters. For example, if I recorded a 1/8th note hi-hat rhythm as MIDI and my performance was a little off, I could use MIDI quantization set to a 1/8th note grid to “snap” the performance back into time. You can think of quantization sort of like a magnet that sucks the notes to a grid, correcting the timing of a piece.
Un-quantized:
Quantized:
MIDI note timing is measured in ticks with 960 ticks in a quarter note. Ticks is a relative time scale and is dependent on tempo to define the bar|beat grid we see in the edit window. By calculating the offset from the grid, Pro Tools knows exactly how many ticks it needs to shift each note to place it into its “quantized” position.
MIDI Quantize Example:
I have a simple MIDI drum performance that feels a little bit off. If we zoom in and examine the notes against the bar beat grid, we can see some discrepancies in the notes position.
Now this could very well be the feel I intended and by no means should everything line up exactly on the grid all of the time. But for this example let us assume that I want a perfect, or completely quantized performance.
I start by first selecting the notes I wish to quantize using either the selector or grabber tool. Pro Tools will only quantize the selected notes, leaving any other notes on the track un-modified.
Next I choose Event > MIDI > Grid/Groove Quantize
Inside the Grid/Groove Quantize menu I have chosen to quantize only the note attacks and have set a grid resolution of a 1/8tth note (since that is the fastest note in my pattern). Now all I have to do is hit “apply” to snap the selected notes to the grid. Because the “strength” parameter is left unchecked, Pro Tools assumes a 100% quantize.
Quantized Performance:
Grid/Groove quantize options:
The key to achieving a performance that feels great is all in knowing what quantize can and can’t do. The quantize parameters inside Pro Tools Grid/Groove Quantize can be set to a number of different values to achieve a specific rhythmic “feel.” By learning and mastering these parameters you can leverage the power of MIDI quantize in almost an infinite number of production or arrangement scenarios.
“What to Quantize”
This section defines which note attributes you want to quantize.
Attacks: Aligns the note start point to the nearest grid value (as defined in the quantize grid parameter). This is the setting generally associated with rhythmic quantizing, you usually will have this setting checked for most applications.
Releases: Aligns note end points to the nearest grid value. Leave this off if you want to preserve your note duration.
Preserve note duration: Preserves note durations by moving end points in unison with start points. When not selected, start and end points can be moved independently, changing the duration of the note.
“Quantize Grid”
Grid menu: Defines the grid resolution to which notes are aligned. This value can be anywhere between a whole note and a 1/64th note. A good starting point for most performances is a 1/16th note.
Tuplet: used to quantize irregular note groupings like triplets and quintuplets.
Offset grid: Offsets the quantize grid by a specific number of ticks. Use negative numbers to achieve a laid back feel or positive numbers to achieve a pushed feel. Remember there are 960 ticks in a quarter note.
Randomize: Moves notes randomly forward and backward after the quantization has taken place.
“Options”
The options menu is extremely powerful when trying to preserve the feel of a performance and mastering this section is the key to quantize satisfaction.
Swing: Shifts every other grid boundary or the “off-beats” (as defined in the grid pop-up menu) by the specified percentage, achieving a “swung” feel. 0% yields no swing, 100% yields a triplet feel. When swing is set to 300%, every other grid boundary is moved to the next grid point.
Include within: Quantizes notes only when located within the specified percentage of the quantize grid. For example: if the selected note is 12 ticks from the 1/8th note grid, a setting of 5% would quantize the note, while a setting of 4% would not. This can be used to quantize the notes that are “pretty much there” and leave notes that are further away alone.
Exclude with: Basically the opposite of include within. Notes that are pretty close are left un-quantized while notes that are further out get sucked to the grid. This setting works great when you have a few really bad notes but for the most part your performance is solid. You can even use include/exclude within in combination to really focus on a specific rhythmic range. If include within is set to 30% and exclude within is set to 25%, Pro Tools would only quantize notes that lie in a 5% margin between 25-30% off the grid.
Strength: Moves notes by a percentage towards the quantize grid. A value of 100% would achieve a total quantize, while lower values can help preserve the original feel of the performance. For example: A note that is 40 ticks off of the nearest grid line would be moved 40 ticks with a setting of 100% and only 20 ticks closer with a setting of 50%. Strength can be used in combination with any of the other parameters to increase or decrease the amount of quantization taking place. If this value is left unchecked, Pro Tools assumes a 100% quantize.
Tips for Quantizing MIDI Performances:
- Unless an extremely rigid feel is desired, try not to set the quantize percentage to 100%. Settings of 95%-99% can be very effective, maintaining just a touch of character while keeping the performance tight.
- Play around with small amounts of swing (say 1-10%). This can help add additional “feel” to a performance, even if an explicitly swung feel is not desired.
- A quantize grid of a 1/16th note is generally a good starting point for most performances. Setting the grid too fine (say to a 1/32nd) can yield rather unintuitive results. Setting the grid to rigid (say an1/ 8th note) can destroy grace notes and fills.
- Remember, quantize is not intelligent. Complex rhythms should be quantized separately or adjusted by hand if necessary. For example, if you have a 1/16th note triplet fill in an otherwise straight 1/16th note hi-hat pattern. Quantizing the entire passage with a straight 1/16th note grid would result in a loss of your triplet fill, while quantizing the passage with a 1/16th triplet grid would result in a total disaster.
- Remember midi notes can be quantized individually or in small groups. For example, you may like the feel of your hi-hats and wish to quantize only the kick and the snare.
- Avoid using too much of the “randomize” parameter. Some people might call this a “humanize” parameter, but I find that humans aren’t necessarily random in the way they perform. To the computer, random is a bit different. Not to get into a conversation on computer programming, but I generally use the “randomize” parameter sparingly.
- Practice using the “include” and “exclude” within parameters. These are very powerful when trying to quantize complex grooves or maintain the specific feel of a performance while correcting only certain notes.
Coming up:
Stay tuned. Next week will dive deeper into MIDI quantize, taking a look at groove templates and input quantize.
Pro Tools Tid Bits:
- Sound Toys Version 3 upgrade now available, now supporting AU and Universal Binary. This paid update fixes bugs and adds new features.
- Waves ships their new L3-LL Ultramaximizer, a multiband peak limiter.
- Waves also announced an incompatibility with their plug-ins and the recently released Apple OS 10.4.9 update. Waves users should not install the update until further notice.
If you have a Pro Tools related question that you would like me to take a shot at answering or have any feedback, please send it to brian@audioMIDI.com. I will do my best to select the questions that seem to stump the most people.
As always, stay tuned to the audioMIDI.com eNews for the latest reviews and new product info.
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