Toolkit: Pitch Manipulation

We tweak the frequencies and explore how both large and small changes in pitch can make a big difference

Broadly, pitchshifting treatments fall into two categories within music production; the processes we undertake in a remedial way to correct errors (using plugins like Auto-Tune or Melodyne), and those we use in a creative context. As you’d expect for the more creative end of the spectrum, there’s no limit to how pitchshifters could usefully make their presence felt. As we’ll see from this month’s walkthroughs, pitchshifting techniques can be used to turn single-line synth parts into ghostly pads. Equally, they can be used for subtle detuning which, in turn, can significantly increase the impact of a single sound as its presence is ‘thickened’ within a track.

Most pitchshifting plugins allow you to make both coarse and fine adjustments to pitch. Coarse changes tend to be pitch offsets in steps of semitones (so 12 steps for an octave, seven for a fifth). Alternatively, you could make a fine-tuning adjustment, measured in cents (there are 100 cents in a semitone). Detune effects are achieved within synthesizers by shifting one or more oscillators in a sound above or below the others, creating a wider pitch base; anything above or below 15 cents in either direction will produce a fairly extreme level of detune. If you’re working with a pitchshifting plugin at the mix stage (rather than within a synthesizer), you’ll be relying on effects to provide such processing and, as a result, the mix dial in your pitchshifter of choice will also prove to be an essential parameter – this sets the blend between the original pitch and the processed pitch. If a part is consistently half a semitone sharp, a -50 cent correction set to 100% wet will shift the entire part down into tune. Alternatively, let’s suppose you wanted to create a ghost harmony which is a fourth below the pitch of the original part; a -5 Coarse offset with a ‘50% wet’ balance will provide an even volume blend between the parts, as it would equally blend the original part and the pitchshifted harmony.

As with so many processes, great results can be made by stacking pitchshifters. Imagine a part with a consistent root note to which you want to overlay harmonies. You could set up a first auxiliary track, route your source sound to it and set up a pitchshifter to create the pitch offset you want. Then, you could set up a second auxiliary track and create a second harmony using a different pitch offset, and continue doing so, progressively adding new harmonies on as many auxiliaries as you like. If you suddenly hear that one part clashes with the harmony, you could use automation to shift the pitch offset to a more appropriate note at that moment. Don’t forget to watch the video this month to see how harmonies can be created for a vocal part within Melodyne.