Correcting timing using the macro
In this tour, you will learn how to work with the quantize time macro in order to correct the timing of notes swiftly and easily.
Correcting timing: the 'what' and 'where' of it
Before examining the operation of the quantize time macro, we should clarify a few basic concepts and relationships. To understand these better, let’s begin by selecting the timing tool.
When the timing tool is active, a position anchor (in the shape of a vertical red line) appears near the start of each blob.

Now check the ‘Show Intended Notes’ option in the View menu.
Grey boxes enclose each blob.

When it first analyzes the material, Melodyne calculates for each note two parameters of relevance to the process of time correction. The first is the intended musical beat of the note; this is indicated by the start of the grey frame enclosing the blob. As you can see, the start of the frame invariably coincides with a grid line.
The second is the actual starting position of each note, which is indicated by the position anchor. This will not necessarily be aligned with the left-hand extremity of the blob. Think of a brass instrument, for example, where each actual note is often heralded by a certain amount of wind noise. Admittedly this noise belongs to the note, but from the standpoint of timing what is of relevance is the moment the sound really unfolds and the pitch first becomes discernible; that is the timing-critical moment.
If you quantize notes with the quantize time macro, the starting point of each note will move towards the left-hand side of its grey frame, with the intensity slider determining whether it goes all of the way, or only part of the way, there – that is to say: to the beat assigned it.

Use of the quantize time macro
Select the notes you wish to edit. If no notes are selected, macro editing will by default affect all notes.
To open the quantize time macro, click on the Quantize Time button in the top right corner of the window.

First, the groove reference (if any) that will govern the time correction must be selected.

If None is selected, the target (or ultimate destination) of any quantization will be the left-hand edge of the grey frame, as already described. This is invariably aligned with the grid line that represents the beat to which Melodyne, in the course of its analysis, assigned the note. (On the whole, the system functions very well; but it can happen that Melodyne gets it wrong, and that after quantization you have to move the note manually to the preceding or following beat.) By selecting None, in other words, you are telling the quantize time macro to move notes to (or towards) the beats assigned them by Melodyne editor based on its own analysis of the material.
None is not the only option, of course, which explains the presence of the radio buttons to its left. The ‘T’ next to the note values stands for the corresponding triplet. If you select 1/4 as the groove reference, to give one example, the grey frames will move to the nearest quarter-note (or ‘crotchet’) and this will then become the ultimate destination for any quantization.
Please note that the time correction macro works differently, and in a more musical fashion, than the quantization typically offered by MIDI sequencers. Instead of simply causing all notes to snap to the selected grid, it edits the points of rhythmic emphasis of the selected notes. If, for example, you take a passage containing successions of sixteenth notes and quantize it to quarter notes, the beginning of each succession of sixteenth notes will be moved to the nearest quarter note. The timing of the semiquavers within the sequence, however, remains unaltered. If you wish to tidy that up as well, you can do so in a second pass, taking each semiquaver sequence in turn and using sixteenth notes as the quantization factor.
The intensity slider determines what percentage of the distance to this ultimate destination the notes will travel in the course of quantization. If you select 0%, for example, they’ll not budge; 50%, and they’ll go half way; 100%, and they’ll travel the full distance, ending up precisely on the beat. You can modify both the groove reference and the intensity of the quantization in real time as the audio plays back; and hear, but also see (from the movement of the blobs in the editing area), the effect of different settings.
If you have already finely adjusted the position of notes using the timing tool, Melodyne will assume you are satisfied with the results; this means that, by default, if you now open the quantize time macro with no notes selected and begin making changes, all notes will be affected except these. If you wish the position of these too to be affected by the macro, check ‘Include notes already edited manually’. The option is grayed out, of course, as being of no relevance, if no manual editing of note positions has been performed.

Exit with OK to keep your changes or Cancel to discard them. Naturally, the fact that you have used the quantize time macro in no way precludes your moving notes at any time subsequently by hand.
If you select a note that has already been edited using the macro and then open the macro again, the settings previously applied to it will be displayed; the macro remembers, in other words, the parameters previously applied to each note. If the current selection includes notes to which different settings have been applied, a mean value for each parameter will be displayed.
Even after exiting with OK, you can still reverse the effects of the macro editing by using the undo function.
A note about time quantization (whether double-clicking with the timing tool or using the macro): With polyphonic material, as well as anchors with triangles, there are anchors without them. Notes the anchors of which have no triangle are in a temporal relationship with another note with a triangle and are therefore treated differently during quantization. If you play a C on the piano and immediately afterwards an E, the C can also contain starting transients belonging to the E. The C here gets a marker with a triangle; the E, one without. To move these two notes for no good reason by different amounts during quantization might not make much sense musically and could even produce tonal artifacts.
The following rules therefore apply: If during quantization both notes are selected, the note with the triangle and that without it will move towards the marker by exactly the same amount. There is here, in other words, a master-slave relationship. If you have only selected the note with the triangle marker, only this will be quantized. If you have only selected the note without the triangle marker, no quantization will take place. The same goes for a multiple selection. Naturally, you can move all and any of the notes manually if you are not satisfied with the way they sound together.