http://proguitarshop.com/earthquaker-... The Rainbow Machine from Earthquaker Devices is a polyphonic harmonizing modulation machine. Utilizing a modern digital signal processing and modern oscillation circuitry The Rainbow creates some real time pitch shifting, but not in the way you are probably used to. The Rainbow Machine will put a new twist on your playing by adding polyphonic harmonies, wild pitch take offs and descends, chaos chorusing, pixie trails, and transformations before your very ears. With the ability to shift from a 4th down through a 3rd up (including a stop at every atonal station in between) the Rainbow Machine tracks perfectly up and down the neck without any of the typical glitch out. Need an accompanying octave with your harmonies? The Rainbow's got it, and we haven't even talked about the "Magic" yet. The Magic is the true soul of this effect with its ability to add "weirdness" where there was none before. If you need an actual technical description, it's a regeneration control that creates aliasing between a mix of the primary and secondary functions feeding back against each other. It has to be heard to be believed.