Olga Podluzhnaya presents from 1:11 biphonation, a unique two-part singing technique. Actually, biphonation is a vocal disorder. It is assumed that the left and right vocal cords vibrate at different frequencies . But here it is an artistic intention and certainly not pathological.
I did a sound analysis of my favorite part at 1:30 to 1:36. There you can see unusual things: the two tones produced at the same time have a gap of 324 cents between the major and minor thirds. This interval does not occur in the overtone series. So it’s really two separate sounds. But they have far too many overtones. The expected overtones are laid over the spectrogram as a diagram. And these can also be seen in the spectrum. But there are still more overtones in between, which cannot come from the two fundamental tones. I don’t have an explanation. Anybody have an idea?
Christopher Vila is the inventor and manufacturer of this ravishing music instrument, that leads you in a deep self-forgetfulness when you play it, what you can still feel as a listener: Cosmicbow.
In the video, he demonstrates an incredible control of the first and second formant, by playing two independent melodies simultaneously with both resonances. He controls the deeper overtone with the anterior mouth, the high harmonics are determined mainly by the position of the epiglottis and the root of the tongue.
This skill is an example of how much music is yet to be discovered in our vocal resonance cavities alone. A reference to the vocal Phonetics is interesting, in which also a control of the formants is required to enable the brilliance and load-bearing capacity of the voice, which is required for classical singing. I can recommend any classical singer to play around with the Cosmicbow for a while.