Quantizing MIDI

the Quantize dialog
The Quantize dialog

Quantizing a MIDI region, usually one recorded from a MIDI instrument, consists in perfectly aligning the notes with the grid by shifting the notes positions to the closest grid line. The result is a perfectly timed MIDI region, allowing to correct rhythmically poor performance.

This dialog is accessed via the Region > MIDI > Quantize... while having a MIDI region selected, or by right clicking a MIDI region, Name_Of_The_Region > MIDI > Quantize... or with the default 5 shortcut and includes:

Snap note start If checked, the start of the notes will be aligned to the grid as defined in the following combo-box (see below)
Snap note end If checked, the end of the notes will be aligned to the grid as defined in the following combo-box (see below)
Threshold (ticks) Defines how close from a grid point a note must be in order to be quantized. Notes farther than this number of ticks will not be affected.
Strength Defines how close to its new position the note must be moved, as a percentage of the nominal distance (allowing for a non-perfect quantization, i.e. just making the performance rhytmically better without giving it a machine-generated feel)
Swing Applies a swing to the midi notes, i.e. delays every 2nd note by this amount, to e.g. simulate a groovy drummer

The grid selection combo boxes allow a choice between the current main grid, or many beat subdivisions.

Both note start and note end can be selected at once, resulting in a 2-pass quantization: the note starts are aligned to the grid (with or without the swing and Strength parameters), then their ends are aligned.

The swing is a value between 0 and 130, and is relative to the user-selected grid type: every note which is considered a second note (i.e. close enough to an odd grid line as per the threshold value) will be delayed by this number of ticks.