At 6:08 Jon describes this as a recent addition to his set up for reverb and harmonizer purposes (video date February 28, 2014). He details how he uses the harmonizer to simply pitch-shift his vocals down an octave for a "weird pseudo-artificial and yet really organic" sound for his vocals.more
After I saw someone use a harmonizer by TC Electronix live, I just had to go home and see whether BOSS had one as well, since I'm a big fan of their effect pedals. Lucky enough they did and I got it straight away. A vocalizer like that with so many different effects and possibilites is really the ultimate playground for every singer, who likes to take his vocal performance to the next level. It really changed my live performance completely and I've been using pretty much every effect for different songs, especially the Harmonizer with an additional vocal a third above my main vocal for the chorus and the Autotune, whenever I feel particularly freaky. One of the best investments I've made so far!
I bought this pedal looking for a multi-effect pedal that I could easily implement on stage into my vocals. This pedal has almost everything you could ask for, the effects sound nice and the interface can be easily used to tweak your effects to perfection with a little practice. The harmonies are a little tricky and if you don't sing exactly on pitch it doesn't sound great. But if you set it up properly with the key it can add some nice stuff. The only thing that I really wish this pedal had was a way to paused and resume the loops you create... The looper works well, it's easy to figure out and use but there is no way to pause your loop or play it only once which really leaves something to be desired especially if you were in a live acoustic setting and were relying on your looper as part of your backing track. None the less it's a solid pedal and it has served me well in the time I've had it.