Folks, I am off to Kansas for the American Guild of Organists’ NYACOP Competition, and then their National Convention. Notwithstanding the possibility of winning, I look forward to meeting many people over the next two weeks (including some of my readers), and hearing some good music! But right now, I’m stuck at LaGuardia Airport, and there is no free Wi-Fi; all I have to pass the time is looking at airplanes.
Keyboard instruments in some sense are the airplanes of the pre-industrial era: among the most complex mechanisms of their respective times (along with the pocket-watch), filled with precisely-fitted parts, and somewhat inscrutable mechanically—almost magical—until one pops the hood. The fact that I spend so much of my life in the air makes a little more sense in this light… Hopefully you will not be offended if this post is partly about airplanes.
I was waiting for my United A320 to show up when, across the window, there went the controversial American 737 MAX, a much-maligned installment in the gradual shrinking of airplane seats. Nevertheless, it has many features that could be called revolutionary. In particular, it is dramatically quieter than planes of an equivalent size—at the back of each engine are chevrons borrowed from the 787, a sort of serrated or “nicked” pattern designed to create vortexes. Essentially, they reduce turbulence as hot air from the turbine mixes with cold bypass air (the mechanism is a little complicated, but the end result is a strong attenuation of high frequencies). Here is a stock photo, because I am a bad photographer:
And here is a picture of a random organ pipe’s mouth:
This mouth is nicked to reduce transient noise on speech by introducing vortexes. An unnicked pipe will “cough” or “sizzle” slightly—a little burst of high-pitched, inharmonic noise—and adding nicks significantly reduces the high frequencies involved. It is a very old trick. If the 737 MAX is indeed the technological descendant of the pipe organ, then it’s nice to see that some very specific engineering lessons have been learned, though what was once learned by trial and error is extensively computer simulated in its newest incarnation. This all raises a question: there are organ aficionados who prefer their instruments unnicked because the sound is “fresher” and more “expressive”; I wonder if they will avoid the 737 MAX? I will join them, but mostly because of the seat pitch…
Hope to see you in Kansas!