In the following performance from home, I used the $300 BOSS Vocoder to sing a half dozen Christmas carols for this Christmas morning by combining MY voice with a second electronically generated voice an octave higher than my own. It's a weird experience to be sure. It actually reminds me of my Aunt singing over my shoulder when I played piano as a little kid. Notice my piano chords as well-- they're not the standard chords in all cases-- lots of "altered chords". Check it out.