Singing this Note is IMPOSSIBLE!

There are a lot of musical instruments that utilize some of the acoustics you've demonstrated here. Brass instruments are the best example. Instead of singing into the tube, the player's lips act like the vocal cords. While there is some flexibility to what frequency the player's lips can vibrate, they only will resonate at the harmonics of the open pipe. If this pipe were conical or had a bell flare, the effect will be different. Something else that is interesting from a physics perspective is the effect of a stopped Horn (where the Horn player inserts their hand into the bell of the Horn to block the air leaving the instrument). In stopping the instrument, the frequency is lowered to a half-step above the next lower harmonic.


Towards the end of the video, you mention how singers match their vocal tract to match the frequency of the note sung. All woodwind and brass players will do this as well. Through the use of this sympathetic resonance, players can change the harmonics produced by their instrument (saxophone players are particularly adept at this).


Perhaps the best visual instrument for this is the Marimba (a percussion instrument - which is actually playing in the background of the video). Underneath the bars of the Marimba, which produce the sound, there are a series of resonators - identical to your PVC pipe. These resonators are tuned to the exact frequency of the fundamental and are used to acoustically amplify the sound which would otherwise be faint.