Elastic Audio in Pro Tools enables you to make timing changes to audio regions (including the ability to quantize) as easily as if it were MIDI, but did you know that you can also make non-destructive changes to the audio's pitch once it has been elasticized?
Any audio region on a track that has been Elastic Audio-enabled can have Elastic Audio pitch transposition applied to it. Previous articles on Elastic Audio (e.g. Fixing Drums with Elastic Audio in Pro Tools) showed how choosing an Elastic Audio plug-in causes regions on that track to be analyzed for transients, which are labelled with Event Markers. As an alternative you can drag a region from the Region List, Workspace, Project Browser, or even the Finder, to an empty track on which an Elastic audio plug-in has already been chosen. The region will be analyzed and ‘elasticized’, automatically.
Dragging an audio file from the Project Browser to an Elastic Audio-enabled track causes it to be ‘elasticized’
Note: Elastic Audio pitch transposition is not available for regions on tracks that are using the Monophonic Elastic Audio plug-in. This can cause confusion as pitch transpositions are often applied to pitched monophonic parts such as vocals.
Elastic Audio pitch transposition can be applied to a region (and it must be a whole region, not just part of a selected region) in one of two ways:
1. Using the Elastic Properties dialog window (choose Region > Elastic Properties or Option-5 on the numeric keypad): in this window you can enter a value for semitones and cents (hundredths of semitones) to a maximum range of two octaves. The pitch changes the next time you play the audio (you need to stop and start if Pro Tools is already playing, for the changes to register). Interestingly, it is also in this window that you can change the Event Sensitivity which reduces, or increases, the number of transient events detected:
The Elastic Properties Window
2. The Transpose Window (choose Event > Event Operations > Transpose or Option-T): this window has sliders for octave and semitone transposition (no cents this time) and although the range of the octave slider is labelled up to 10 octaves in either direction, the maximum total pitch shift allowed is still two octaves (24 semitones). Once you click Apply the pitch shifted in the Event Operations window is also shown on the Elastic Properties window.
The Event Operations window also allows you to define the pitch ‘from’ and ‘to’ which you transpose (useful if you think in musical intervals) but the other two options shown are not available even though you can select them (see image below).
The Transpose dialog window.
Because Elastic Audio pitch transposition takes place in real time, you can always return the region to its original pitch with no loss of quality. Just enter zeros into the pitch fields in the Elastic Properties window, or choose Region > Remove Pitch Shift.
‘Elastic’ Pitch Transposition can also be achieved by using the Varispeed Elastic audio plug-in, but only if you speed up or slow down the audio either by using the TCE Trimmer tool to perform time compression or expansion on the whole region, or change the tempo (the track must have a a tick-time base for this to work (see image below).
Choosing the Varispeed Elastic Audio plug-in.
If you choose the Varispeed plug-in, any changes made to the pitch in the Elastic Properties or Event Operations windows will be ignored, but will be reinstated if you revert to one of the other plug-ins (not the monophonic plug-in of course!). You can use this feature to compare different methods for creating pitch changes to audio.