Harmonica players tend to play traditional roots-based styles (like blues) with traditional equipment, and lots of harmonica players have never tried out the sorts of FX that guitarists have been using with great success for a long, long time. We’re going to talk about one of those FX in this post, the one that I think EVERY harp player should try (right after they’ve picked up a decent delay or reverb pedal): a pitch shifter.

A pitch shifter does what its name implies: it takes an incoming signal (like a harp coming through a microphone) and adjusts the pitch of that signal up or down. A pitch shifter makes a powerful addition to any harmonica rig, especially in terms of adding low octaves and other low intervals to the original pitch. Harmonicas put out a lot of energy in the high register to begin with, and in my opinion the added weight of low octaves makes for a better sound than additional top end. (of course, if you’re playing a Hohner Thunderbird, which is pretty far down in terms of pitch to start with, you might be better off with more top end.) My performance of Morphine’s “Early to Bed”, recorded live at a gig in Victor, Idaho using an RP355 with my patch set is an example of how much weight and power a low octave or double octave can add to the harmonica’s basic tone.

This kind of rock material isn’t “traditional” roots music, of course, but you can use the same kinds of sounds to fill the role of a tenor or bari sax in a blues band. I’m not talking about imitating a sax; I’m talking about filling the same frequency range with something that has a similar reed-instrument sound. Even a traditional blues band can find a use for that. (Certainly some of the ones I’ve played with have.)

POG2 pitch shifter
POG2 pitch shifter

Wade Schuman’s work with Hazmat Modine is an outstanding example of how to use a pitch shifter with harmonica. Wade uses an Electro-Harmonix POG, a device that generates one or more pitch-shifted octaves simultaneously, including low and high octaves and double octaves. The Electro-harmonix HOG, a more complex (and expensive) device, adds low and high 5ths, octaves with added fifths or thirds, and so on for a total of up to ten simultaneous pitch-shifted intervals, which makes for a pretty big roar when you crank it up.

The POG2, Electro-harmonix’s latest version of the POG, sells new for over $325. As an alternative, consider any of the Digitech RP series of devices coupled with my patch set for Digitech RP. These units can generate one pitch-shifted voice at a time, which can be set to any interval from two octaves down to two octaves up, and can be mixed in any desired proportion with the original voice. In the RP255 and higher models in the RP series, either the pitch shift interval or the pitch shift mix can be put under footpedal control for real-time manipulation of the sound, and can be combined with a range of other FX that include wah, delay, reverb, and distortion. Even the RP155, which sells for less than $100 new, produces an excellent pitch shift effect, which makes it one of the lowest-cost pitch shifters available (not even counting the other FX in the box), and undoubtedly the best single-voice pitch shifter available in a multi-FX device in that price range.

Any RP from the 255 up can use the whammy effect, which pitch-shifts smoothly within a given range, say from one octave down to normal pitch, including anything from single notes to chords, under footpedal control. (It’s the whammy that creates the careening pitch shifts during the solo on “Early to Bed.”) The RPs also include a harmonized shifter that will harmonize original tones with a key- and scale-consistent interval (for example, 3rds in the key of E minor); I haven’t played with it much, but it’s an interesting effect for tunes where you know what key and mode you’re going to play in.

Digitech RPs do great one-voice pitch shifting at a great price
Digitech RPs do great one-voice pitch shifting at a great price

I’m partial to the RP series devices, which in my opinion offer very high value for money given that they include so many other FX along with the pitch shifter. The Zoom G3 also contains a decent pitch shifter, though not as robust as the RP’s in my opinion in terms of either basic tone quality or tracking. However, the G3 allows you to chain multiple pitch shifter modules in series, which lets you generate some complex tones that aren’t possible on an RP. (By “in series,” I mean that the pitch shifters run one after the other in the signal chain, so the second shifter in the series acts on the first, the third shifter in the series acts on the first and second, and so on. In the POG, the shifters run in parallel, so you can adjust one without affecting the others.) With a G3 you can generate chords from a single original note that span 4 or more octaves; for example, start with a double-octave down shift; then add an octave up, which gives us a chord that includes the original note, the same noted shifted one and two octaves down, and the same note an octave up. Add a shift of a 5th up to all that and you have a series of roots and fifths spanning four octaves and a 5th. Of course there’s a certain amount of signal degradation going on with every added pitch shifter, but still, we’re talking about a very big, wide sound. Better make sure you’ve got something bigger than an 8″ speaker in your cabinet if you want to run that lineup, or you’ll blow the speaker cone to bits the first time you crank it up.

The Zoom G3 does multiple-voice pitch shifting on the cheap, with a little less quality in the sound than an RP
The Zoom G3 does multiple-voice pitch shifting on the cheap, with a little less quality in the sound than an RP

In any pitch shifter, the things to look for are:

  • Rapid response to notes over a wide frequency range. Some earlier pitch shift designs, such as the Boss OC-2 Octaver, track very poorly on the harmonica above the middle octave. Others introduce a noticeable lag into the shifted notes, which is not ideal for fast playing, or for any other situation where accurate timing matters.
  • The ability to accurately track chords as well as single notes. Here again earlier designs like the OC-2 just don’t cut it. Devices like the POG and Digitech RPs reproduce chords accurately.
  • The ability to mix the original and shifted tones in any desired proportion, ideally in real time.
  • The ability to adjust the shifted tones to any desired interval, again ideally in real time. The RP devices are more flexible than the POG in this respect, though the POG allows simultaneous shifting to multiple octaves, along with the ability to adjust the mix on every shifted octave individually.


  • Remember that a pitch shift of an octave down or two octaves down creates low-frequency pitches with loooong wavelengths, and if you do a lot of that stuff you’re going to need an amp with a 10″ speaker at least. If you want to do a whole lot of low end, consider a keyboard amp or powered PA speaker with a 12″ or 15″ woofer.

    I love pitch shifters. The first time I ran a harp through a Digitech RP with a low octave pitch shift, over ten years ago in an instrument store, less than thirty seconds elapsed before I picked the thing off the floor and walked it to the checkout counter. The most important effect for any electric harp player is a delay unit, and a pitch shifter is a close #2 in my opinion. It adds weight and power to any amped harmonica setup, to the point that it changes the game for the player. If you’re playing anything but purely traditional styles, a pitch shifter ought to be in your rig.