Pitch Correction/Pitch Shift

Pitch correction, often referred to as “Auto-Tune,” is a tone-based tool, used primarily to adjust the intonation of recorded vocal tracks, though it can be used on any instrument. It is also sometimes used as a creative effect.

Pitch correction is unlike the other tone-based effects we’ve covered, in that the mechanism by which it works is much more complex, so complex, in fact, that I won’t go through all of the math that makes it work. All you need to know is that the pitch corrector analyzes the audio source, determines the changes needed to produce the desired outcome, and then makes those changes, based on how the parameters have been adjusted. There’s a wide variety of options when it comes to pitch correction, from hardware to plug-ins to tools that are built right into your DAW. The most flexible versions of the tool will include parameters that allow you to adjust not only the pitch of a sung note, but other vocal qualities as well, including timbre, vibrato, and scooping. Pitch shift refers to a simpler kind of pitch correction, usually in plug-in form, that works by a less complex mechanism. A pitch shifter does not need to analyze the audio source before it starts working. Instead, it simply uses an algorithm to transpose the entire clip or track up or down by the desired number of semitones and/or cents. (A cent is 1/100th of a semitone.) This is useful for creating a copy of a recorded track that plays back simultaneously at an octave or some other interval higher or lower than the original, without the need to record an additional take.

Pitch correction and pitch shift are advanced tools that some producers will rarely, if ever, need to use. But particularly for those who produce any form of pop music, broadly speaking, these tools can come in handy in a variety of ways. They can be used to clean up a sloppy vocal recording, create harmonies from existing tracks, or, when the song calls for it, produce that perfectly-tuned, robotic effect that has become so common in hip-hop and contemporary R&B.