What Are Pitch-Shifting Guitar Pedals & How Do They Work?


Pitch-shifting pedals, and those pedals that utilize pitch-shifting, are among the most amusing to play through and can truly open a whole new realm of sonic and harmonic capabilities on guitar, bass and other instruments.

What are pitch-shifting guitar pedals and how do they work? A pitch-shifting guitar/bass pedal is a stompbox unit that affects the pitch (frequencies and note value) of the input signal. The pedal may output the shifted signal or a mix of the direct signal and shifted signal(s). These pedals read the harmonic content of the input and shift it accordingly.

In this article, we’ll discuss dedicated pitch-shifting pedals in much more detail along with the other effects types that utilize pitch-shifting in one manner or another. I’ll share a few pedal examples along the way and tips on how to get more out of your pitch-shifting pedals.


Table Of Contents


What Is Pitch?

Before we get into our discussion on pitch-shifting pedals, it’s important to define what pitch is.

The first thing to point out is that pitch is a subjective/perceptual property of sound (that translates into audio). The electronics (whether analog or digital) found in pitch-shifting pedals, however, act objectively. This discrepancy is worth noting before we begin.

Musical pitch is a perceptual property of sound that allows listeners to qualify different sounds as being higher or lower in terms of musical notation. This auditory sensation allows us to relate the positions of different notes within the context of a musical melody.

Musical pitch and notation are related to frequency, though not entirely linked. The fundamental frequency (the lowest frequency of a note being played by a tuned instrument) is generally the most linked to musical pitch.

A note with a higher fundamental frequency will be higher in pitch. A note with a lower fundamental frequency will be lower in pitch.

Note that pitch is truly only applicable to tuned instruments. Percussive instruments like cymbals and drums can be “tuned” but typically lack a distinct musical pitch. Noise also has no pitch, generally speaking.

That being said, all these sounds have frequencies within the audible spectrum.

The exact note value of a given pitch (with its fundamental frequency) is largely determined by the tuning system used.

In western music, the two most common tuning systems are 12-tone equal temperament with A4 = 440 Hz or A4 = 432 Hz

I’ve written about the relationship between pitch and frequency in my article Fundamental Frequencies Of Musical Notes In A=432 & A=440 Hz if you’d like to check that out.


How Does Pitch-Shifting Work?

While pitch alterations are obviously possible on tuned instruments, pitch-shifting is a purely electrical occurrence where an audio signal is manipulated to sound higher or lower in pitch.

The easiest way to achieve pitch-shifting is by speeding up or slowing down audio. This pitch-shifting is a by-product of time-shifting and is often referred to as “pitch controlling”.

This can be done by playing an audio file at a different speed than it was recorded. For instance, we could change the sample rate of a digital audio workstation from the sample rate the audio was recorded in. Another example would be to adjust the motor speed of a reel-to-reel tape recorder.

Note that time stretching is process of changing the speed/duration of an audio signal without altering the pitch and that pitch scaling is the process of changing the pitch without altering the speed.

However, this isn’t how pitch-shifter pedals work. Pitch-shifting pedals need to act in real-time.

Pitch-shifting, as the name suggests, works by altering the pitch of the input signal and outputting a signal with a different musical note. It does so via electrical means, bringing objectivity to the perceived nature of musical pitch.

Pitch-shifters can be monophonic or polyphonic.

Monophonic pedals can only affect one note at a given time and are easily overloaded if any additional frequency information is included in the input signal.

Polyphonic pedals can distinguish between notes in a given signal (between fundamental frequencies of certain notes and harmonics from other notes) and affect more than one note at a time, allowing chords to be pitch-shifted up or down.

Some pitch-shifters will only output the shifted/affected signal. Others can output a blend of the pitch-shifted and direct signal, allowing for harmonization with the input notes. Some other pedals can produce multiple copies of the input signal and pitch-shift these copies differently.

We’ll get into the various designs shortly.

Simple octave pedal circuits can be produced via analog circuits that alter the frequency and filter the signal to attain the desired effect. These analog circuits are monophonic.

Analog octave circuits may also sound noisy and “warbly” as they attempt to track the input signal.

Today, many octave pedals and practically all pitch-shifting pedals (including pitch-bending, harmonizing and transposition-type pedals) achieve their effect via digital signal processing (DSP).

The DSP within pitch-shifter pedals typically utilizes frequency-domain shifting based on phase vocoder techniques and algorithms based on short-time Fourier transform (STFT). These processes allow the pitch to be changed in real-time and are relatively simple compared to many time-domain shifting processes.

The inner workings and designs of the digital signal processing units are beyond the scope of this article. Just know that pitch-shifting pedals are nearly all digital and they work by altering the note(s) of the input signal.


Pitch-Shifting & Harmonizing Pedals

Now let’s get into the different types of pitch-shifting pedals and go over some examples.

The 4 main types of pitch-shifters, in the modern market, each make up their own type of pedal. However, they are all, at their core, pitch-shifters. These pedal types are:

Octave Pedals

Octave pedals, as the name suggests, produce octaves above and/or below the determined pitch of the input signal.

The octave pedal was the first type of “pitch-shifter” to be invented and is the most popular type of pitch-shift circuit to this day. This effect can be achieved via analog or digital means.

Putting an octave below a guitar signal can give us the sense of an additional bass line. Similarly, putting an octave above a bass can give a sense of an additional guitar line.

Adding multiple octaves to a guitar or bass signal can bring us close to the sound of an organ. Affecting these octaves can bring into a synth-like sonic territory, which we’ll touch on later in this article.

The Boss OC-3 (link to check the price on Amazon) is an awesome octave pedal with inputs designed to track guitar or bass guitar.

The OC-3, like the OC-2 before it, offers additional octaves at both 1 and 2 octaves below the input signal. This pedal also has a polyphonic mode along with an overdrive circuit to add some extra grit to the output signal.

Boss OC-3

The TC Electronic Sub ‘N’ Up (link to check the price on Amazon) is another great example of an octaver pedal.

This pedal offers a classic (monophonic) mode with imperfect tracking along with a polyphonic mode for improved tracking and the ability to affect chords. There are four distinct octaves, each with its own level control:

  • 2 octaves below
  • 1 octave below
  • dry signal
  • 1 octave above

We can dial in our own sounds or use TC Electronic’s Toneprint technology to send presets to the pedal wirelessly from an app on our smartphones.

TC Electronic Sub ‘N’ Up

Boss and TC Electronic are featured in My New Microphone’s Top 11 Best Guitar/Bass Effects Pedal Brands To Know & Use.

Harmonizer Pedals

Harmonizer pedals allow for much more than simple octaves above or below the dry signal. These digital pedals will typically offer the choice of several intervals above and/or below the note(s) of the input signal.

The idea behind these pedals, as their name suggests, is to provide harmony to the musical notes being played. They will always offer a wet/dry mix to blend the direct signal with the pitch-shifted signal.

To achieve musical harmonization, these intelligent pedals are often programmed to latch into a diatonic key (like major/Ionian or minor/Aeolian). This allows the pedal to alter the pitch of the chosen interval to match the sound of the scale.

Without getting too deep into theory, let’s look at an example. Let’s take the C major scale and look at the third harmonies of each of its notes. Notice that some thirds are major (4 semitone difference) while others are minor (3 semitone difference). A harmonizer pedal designed to working within musical keys will pick up on these differences and affect the signal accordingly.

Harmonizer pedals will typically be capable of producing the octave effect but octave pedals will not be able to do what harmonizers can.

The TC Electronic Quintessence (link to check the price on Amazon) is a perfect example of an intelligent and versatile harmonizer pedal.

It offers all 12 musical keys in western music along with 6 of the 7 modes (“scales”) of each key (no one uses Locrian, the seventh mode, anyway!) and a custom scale for non-diatonic harmony. Note that the Key control establishes the root note while the Scale control starts the scale on the root note.

The harmony control offers several interval options including a few for triads (chords with 3 notes). The options are:

  • 6th below
  • 4th below
  • 3rd below
  • 3rd above
  • 5th above
  • 6th above
  • 3rd + 5th above (triad)
  • 3rd + 6th above (triad)
  • 3 user-defined Toneprint preset (which can be applied wirelessly from an app on your smartphone)

The pedal is complete with a mix knob to blend the dry and wet signals together.

This pedal also offers latch or momentary options with its footswitch along with MASH technology that turns the footswitch into a pressure-responsive expression controller, allowing pitch-bending between notes.

TC Electronic Quintessence

Transposition-Type Pedals

Transposition-type pedals act to transpose your entire instrument up or down in pitch.

With a transposition pedal, we can drop tune without changing guitars (or manually tuning, which may be awkward to do during a performance). If the pedal offers upward transposition, we can throw away our capo and use a pedal instead.

These pedals aren’t all that common on the market but are worth mentioning here.

The best example of a “transposition pedal” is the DigiTech Drop (link to check the price on Amazon).

This polyphonic “pitch-shifter” tracks incredibly well and offers 9 different options for drop-tuning the guitar with 1-7 semitones down; full octave down, and a full octave + direct/dry signal settings.

DigiTech Drop

DigiTech is featured in My New Microphone’s Top 11 Best Guitar/Bass Effects Pedal Brands To Know & Use.

Pitch-Bending Pedals

Pitch-bending pedals are hands down the most fun pitch-shifting pedals of the 4 we’re discussing here.

Even better is that practically all pitch-bending pedals will have some functionality from the previous three types.

Pitch-bending pedals bring time into the equation and can gradually shift the pitch of a note from one pitch to another. This can be done via an envelope, as we’ll see with the Boss PS-6 or via an expression pedal, as we’ll see with the DigiTech Whammy 5.

The Boss PS-6 (link to check the price on Amazon) is a harmonizer pedal at its core with octave capabilities along with key control; interval settings (including triads) and minor or major modes. As we’d expect the pedal also has a mix control to blend the direct and wet signals.

This pedal offers a variety of pitch-shifting effects, engaged via the pitcher shifter mode and controlled with the rise time (balanced knob), fall time (key knob), and a momentary footswitch.

The pedal also features a detune mode, which we’ll cover in the next section.

Boss PS-6

The Electro-Harmonix Pitch Fork (link to check the price on Amazon) is fairly straight-forward in design but powerful in its sonic effect.

The pedal offers several intervals to choose from and allows users to choose whether the pedal goes up the set interval, down the set interval or up and down. This can lead to some interesting effects.

The blend knob mixes the dry and wet signals together and the latch button switches the footswitch between latch to momentary functionality.

But that’s not all. The expression input allows us to connect an expression pedal to the pitch fork and control the pitch-bending ourselves via a treadle-type controller.

Electro-Harmonix Pitch Fork

The DigiTech Whammy 5 (link to check the price on Amazon) is the modern version of the legendary Whammy pedal that started it all in terms of pitch-shifting guitar effects.

DigiTech Whammy 5

The pedal offers expression pedal-based pitch-shifting between 10 intervals. It 10-mode harmony section offers dual voices with different intervals at each extreme of the treadle (toe-down will give one interval while heel-down will give another).

Octaver settings can be achieve with one octave up + dry and one octave down + dry. Harmony can be achieved via any of the 10 harmony modes.

Transposition is also possible, though there are other pedals on the market that track much better than the Whammy.

The pedal also has a classic mode, more suitable to monophonic inputs and a chords mode that is better suited to hand polyphony.

Finally, the Whammy 5 offers two detune settings (shallow and deep), further improving the versatility of this awesome pedal.


Pitch-Shifting In Other Effects

So we’ve discussed the pitch-shifter pedals in detail. However, there are other effects that utilize pitch modulation and shifting that are not necessarily “pitch-shifters” in the classic sense. Let’s investigate to find out more about these other pitch-based effects.

Here is a list of other effects pedals that alter the pitch of the input signal in order to achieve a desired effect.

Vibrato Pedals

Vibrato is a fast up-and-down variation in pitch that is achievable naturally with the human voice any many pitched instruments. It’s also achievable with electronics. That’s where vibrato pedals come in.

A vibrato pedal will utilize a low-frequency oscillator (LFO) to control the pitch of the signal by moving its frequency/harmonic content. The vibrato effect is then controlled mostly via the rate/speed control of the LFO and depth/amount of pitch-shifting that takes place.

The Boss VB-2W Waza Craft (link to check the price on Amazon) is a great example of a vibrato pedal with rate, depth, rise time and mode controls.

Boss VB-2W Waza Craft

For more information on vibrato pedals, check out my article What Are Vibrato Guitar Effects Pedals & How Do They Work?

Shimmer Delay/Reverb Pedals

Shimmer effects can be thought of a two-effects-in-one deal:

  • Shimmer delay is like a delay with a direct out and a wet/delayed signal that is pitched up via a pitch-shifter.
  • Shimmer reverb is like a reverb with a direct out and a wet/reverb signal that is pitched up via a pitch-shifter.

The Electro-Harmonix Canyon (link to check the price on Amazon) is a great example of a shimmer delay pedal, combining delay with pitch-shifting.

Electro-Harmonix Delay/Looper Pedal

The Strymon Big Sky (link to check the price on Amazon) is a great example of a digital delay pedal with a shimmer option.

It features the following emulations:

  • Room
  • Hall
  • Plate
  • Spring
  • Swell (a different take on the bloom-type reverb)
  • Bloom
  • Cloud (a cathedral-type reverb)
  • Chorale (a reverb combined with wah-like filtering)
  • Shimmer
  • Magneto (a reverb and delay effect emulating tape warble and echo)
  • Nonlinear (a non-linear, unnatural and programmable reverb)
  • Reflections (focuses on early reflections and sounds similar to a stereo delay)
Strymon Big Sky

To learn more about delay and reverb pedals, check out the following My New Microphone articles, respectively:
What Are Delay Pedals (Guitar Effects) & How Do They Work?
What Are Reverb Pedals (Guitar Effects) & How Do They Work?

Synth Pedals

True synth pedals are actually designed as synths with built-in oscillators that are simply controlled by an inputed guitar or bass signal.

However, some pedals are awarded the “synth” description if they simply sound like synth. Pitch-shifting (particularly octave stacking) can turn a normal guitar signal into a synth-like audio signal. Combining that with other effects and filters can produce a sound that is more closely related to a synthesizer than a guitar.

The famous Electro-Harmonix POG2 (link to check the price on Amazon) is a polyphonic pitch-multiplier “synth” pedal allows us to stack 4 octaves in addition to the dry sound:

  • -2 octaves
  • -1 octave
  • +1 octave
  • +2 octaves

The polyphonic octave generator also features an attack control (ADSR), a low-pass filter, and a detune (chorus) function.

Electro-Harmonix POG2

For more information on Synth Pedals, check out my article What Are Synth Pedals (Guitar/Bass FX) & How Do They Work?

Detune Pedals

Detune is an interesting effect. It is an effect that is sometimes included in pitch-shifting pedals (like the aforementioned DigiTech Whammy 5 and Boss PS-6).

What detune does is it duplicates the signal (as any pitch-shifter does) and alters its pitch by cents of a semitone (rather than by specified intervals).

The result is a thickening of the signal and a sound similar to a chorus pedal.

Note that chorus pedals, which are plentiful on the market (unlike the detune effect) are different in their approach.

Chorus produces one (or more) copies of the input signal and modulates the phase of each copy. By altering the phase of the copied signal(s), the effect produces a varying delay relative to the original along with a vibrato-like effect due to phase-shift (similar to a mini, electrical Doppler effect).

The chorus pedal then outputs all voices to produce a widening/thickening of the sound.

Electro-Harmonix and Strymon are all featured in My New Microphone’s Top 11 Best Guitar/Bass Effects Pedal Brands To Know & Use.


Tips On Using A Pitch-Shifting Pedal

Whether you’re thinking about getting a pitch-shifting pedal or are looking to get more out of the pedal(s) you’ve got, these tips should provide some assistance in getting the most out of a pitch-shifting pedal:

Choose The Right Pedal For The Job

Know what you want out of your pedal and choose one that fits that job description.

If you’re “only” looking for an octave function, go with a pedal that offers excellent tracking with octave functionality.

If you want a fully-functional pitch-bender, get one of those.

If you’re looking to grow into a pedal, choose one that you think will come in handy in the future and learn how to use it to its fullest capacity.

Start With Octaves

The easiest function to use on any pitch-shifter is the octave. Work with these and get to know your pedal before diving into the other settings.

Learn Music Theory And Harmony

When it comes to harmonizing with intervals other than octave, music theory can really take your pitch-shifter pedal usage to the next level.

Learn the diatonic scales and modes and their different intervals. Get to know the inversions and develop a sonic relationship with various modes to get the most out of harmonization.

Put The Pedal Before Distortion

As we’ll discuss in a moment, pitch-shifter pedals sound best at the front of the pedal chain. This typically means putting the pedal before any other effects, including distortion and overdrive, and putting the pedal before the amp input rather than in the amp’s effects loop.

For more information on distortion pedals, check out my article Guitar Pedals: Boost Vs. Overdrive Vs. Distortion Vs. Fuzz.

Experiment After Delay And Reverb

If your pedal set up is clean and you’re running a clean guitar signal through a delay or reverb, try sending the direct out to one amp or input and the wet signal into a pitch-shifter. This will yield a neat shimmer effect with, perhaps, some extra functionality.

Play Through The Neck Pickup

Playing through the neck pick up will often give a subtler tone with less in terms of upper harmonics. This can improve the tracking of pitch-shifting pedals versus using the often-brighter bridge pickup.


Where Should Pitch-Shifting Pedals Go In The Signal Chain?

Pitch-shifting pedals are typically finicky devices, especially if they are designed to be polyphonic. Any additional frequency content or signal modulation can severely affect the pedal’s ability to “read” the input signal.

Remember that pitch-shifting guitar or bass pedals obtain all their information from the input signal. A clean guitar signal will present the pedal with the cleanest possible information since these pedals are designed to “look for” the harmonic content of a guitar (or bass) signal to discern individual notes.

Having extra harmonics (from effects like overdrive, distortion, compression, fuzz, etc.) can throw off the clean balance of harmonics and lead to phasey/warbly results from the pitch-shifter.

Modulation effects that alter the phase and frequency content of the signal are also to be avoided before a pitch-shifter. Chorus, phaser, flanger, vibrato, and other modulation effects will trip up the tracking of the pitch-shifter.

Finally, time-based effects (delay and reverb) should also come after pitch-shifters since these effects will also trip up the pitch-shifter’s input tracking.

So then, where should a pitch-shifting pedal go in the pedal signal chain? The answer is “as close to the beginning as possible”.

To learn more about ordering pedals in the signal chain, check out my article How To Order Guitar/Bass Pedals (Ultimate Signal Flow Guide).


How does a guitar effects pedal work? Guitar (and bass) pedals affect the incoming guitar/bass signal in a wide range of ways in order to produce a specified effect. Pedals work with analog and/or digital circuits to change/route the waveform of the guitar signal or to extract and display information about the signal.

To learn more about how guitar pedals work, check out my article What Is A Guitar Effects Pedal And How Do Pedals Work?

What pedals should every guitarist have? Every guitarist is different and would benefit from different pedals (if at all). There are no particular “must-have” pedals for guitarists. That being said, common pedals to consider include tuners; boosts/preamps; overdrive or distortions; choruses; delays; reverbs, and wah pedals.

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