I had the idea for this one while I was filming a microwave video.
Outside, the San Francisco fog was rising and disappearing off of the hills, then re-condensing as clouds above. It was mesmerizing. The ever-rising effect of this fading in-and-out reminded me of Shepard tones, and I thought, I should film this and then attach Shepard Tones to it, as a quick second-secret-channel video! (of course, first I had to wait another 5 minutes and 56 seconds.)
I didn’t know if there were any copyright-free Shepard-Risset glissandos out there, but I thought I could probably make my own using my voice (I’d done something similar to this effect in Twelve Tones already). And as long as I was using my voice, well, wouldn’t it be funny to have lyrics, that were an explanation of what Shepard tones are? Maybe just a quick definition, repeated over and over.
When I’m using just acoustic instruments, I have a good sense of exactly how anything I imagine in my head will turn out, but I have less experience combining acoustic stuff with digital effects like the frequency shifting used in this video. The first test surprised me with how effective it was, and suddenly the video concept shifted to be the video you see above. The only thing that remained was to write, record, film, and edit the thing. And to stop listening over and over to what I’d recorded so far, long enough to actually do more work. That was the hardest part.
All the audio was recorded and edited in Audacity, using the “Change Pitch” effect for the stuff out of my own vocal range (which meant sometimes singing a harmony a perfect fourth down from where I ultimately wanted it to be, while listening to the audio in the original key, for example, which is fun).
The “random Shepard tones” section uses the 12 tone row heard in “The Process By Which Repeated Opinion Becomes Fact“. Most of the recording throughout Shepard Tones was improvisational. So to sound somewhat random to the ear at the beginning of that section, but have it not-random enough that I could remember it while recording each next layer of voices, I chose that row. Familiar enough to my own ear to sing, but not at all familiar to most viewers.
The sound track to the video is downloadable here. The whole video (including soundtrack) is CC-by; feel free to use any part of it however you like.