Digitech Harmony Man Intelligent Pitch Shifter

Twin-stomp pedals have become big in recent years. While the fortunes of multi-effects seem to have waned in the glow of the boutique pedal revolution, twin pedals that just do one thing exceptionally well and with more parameters or memory options are a welcome addition to our pedalboards.
The funky red metallic Harmony Man is as sturdy as a house. The controls aren't too complex and the connectivity is basic, but this is a powerful tool because it can generate musically-correct harmonies based on your chord progression. You can choose from four different types of pitch-shifting and add two different voices to accompany your playing - a third or fifth above or below, an octave up or two octaves below - and there are 24 semitones and four ‘detune' variations to get your head around.
There's a lot of music in this box. You can edit, store and recall four memory presets, and a second guitar player (or loop pedal) can plug in to provide a rhythm guitar source while you solo. There's also an onboard tuner, so you can clear an extra space on your pedalboard.

In Use
For Manual mode, press and hold the right footswitch and play a chord to set your key. The little lights of the Harmony Key Display rotate clockwise until your input is detected, whereupon one light turns green. If you don't want to set the key for every song, engage the MusIQ button and the unit will automatically set the harmonies in relation to the chord pattern you play. The left footswitch is for effect on/off, and the type of pitch shifting is set by the two rotaries on the left. Twiddle them until you find something you like, or plan your attack musically: Triad Shifting bases the harmony around root, third and fifth, Scalic Shifting creates harmonies that are always in the current key. Chromatic Shifting transposes by a fixed number of semitones, and Detune Shifting creates chorus and 12-string effects.  
With near-faultless pitch recognition and tracking, you can surround your playing with harmonies of huge variety and complexity. The Mix knob is very useful, as too much harmony is an easy way to achieve some extremely saccharine sounds. It doesn't all have to be pretty, of course, and some very evil tones can be conjured up too. The Send/Return feature for a distortion pedal means you can achieve chord recognition against the clean signal but apply the actual pitch shifting post-distortion. It's all very well thought out.   

The Allman Brothers, Thin Lizzy, the gloriously absurd Racer X - twin guitar harmony playing goes in and out of fashion. A pedal like the Harmony Man lets you do all the work yourself, but the danger is that you'll end up sounding like a trade show demonstration because there's no player interaction to mediate the feel. It's just you and a bunch of hardware generated tones, even if they are musically correct - so you'll have to dig in and really learn this pedal to get the best out of it. Used with an appropriate ‘less is more' attitude and some thoughtful creativity, this is a powerful, well-engineered, tuneful tool.