How is this possible 
Is there maybe a fipple wedge in the end that he’s blowing into? I don’t know how you’d get the higher pitch with the same air column though. Or for that matter, how you’d get two different notes in the same air column, unless maybe they’re part of the same harmonic series? It’s a puzzlement.
??? I thought maybe he was vibrating his lips. Never mind…
The guy on the butt end of the flute is sounding it similarly to a quena/shakuhachi/California-style Native American flute by blowing across the far edge. Not all that dissimilar to splitting the air column on the far side of a transverse flute headpiece.
Best wishes.
Steve
I get how he’s making sound, but I don’t get how to notes are occupying the air column at the same time. It seems like there would have to be a barrier in the middle of the flute, so it’s effectively two flutes
Drop two stones in still water, a short distance apart. Notice how the ripples from each stone retain their identity as they pass over the ripples from the other. I wouldn’t have guessed it would apply to sound waves in a tube like that, but of course it should. It works with all the other waves I can think of.
Without going frame by frame (if that term still applies to video), I’d hypothesize that at all times there is a hole being vented below whatever note each of the two is playing. That way their vibrating air columns might not collide or at least have significant impact on each other. If that’s not the case, then maybe magic…
Best wishes.
Steve
I was thinking there would be phase cancellation as two similar notes were sounded at the same time–at the very least you would expect that overtones would be phase canceled
Try it yourself. Take two PVC whistles, and join their bottom ends with a pipe connector. Get one person playing each end. You can play independent notes on the two whistles. It does get a bit tricky when all the holes are closed, because you are each playing what amounts to a long overtone flute with competing air streams, but you can still hear two notes.
Ha ha yes “get one person playing each end” is the hard part. Whistle players aren’t exactly thick on the ground around here!
Get a U-shaped connector and try playing both whistles yourself…
Best wishes.
Steve
Diabolical, Steve. Brilliant, but diabolical. Rubber tubing, perhaps?
: 
I just think it’s cool that someone would even think about doing something like this AND to have it sound awesome! I’m going to try “quena”-ing on the foot end of my Boehm flute!
Pat
Let us know how that works! My two “Irish” flutes don’t have a C foot that are open enough to try it.
[Thread revival. Mod]
I’m super late to the party, but seeing the way the guy had to contort his body to play made my Bach hurt!
I’ll let myself out.
Seriously though, this impressed me to no end.