ChatGPT Flute Making Advice

[shrines]

Thanks, Geoffrey. The easiest thing for me to do is modify my bore taper and see what happens. I'll give that a try before I dive back into all the programming necessary to recreate Yang's work.

[Terry McGee]

What originally struck me as interesting about the ChatGPT response was the statement that a longer taper flattens the higher notes. I guess the only way I'll find out is to extend the taper and see if it makes a difference. Now I have to figure out whether to extend the taper toward the headjoint or toward the foot.

Isn't the Reductio ad Absurdum of a "longer taper" the cylinder? And we know that a cylindrical flute flattens the upper notes.

So does a tapered tube sharpen the upper notes, or flatten the lower notes to equal them? "Hello, ChatGPT, I have a further question for you....."

[Tunborough]

Bore Diameter: The bore diameter of a flute affects the tuning of the high notes, including those in the third octave. A larger bore diameter will produce sharper high notes, while a smaller bore diameter will produce flatter high notes.

Interesting. This conflicts with my own experience. Using a larger bore for a given key most certainly does NOT sharpen the high notes--quite the opposite.

That's the thing about chat-bots. When they don't know the answer (and really, they never "know" any answer), they make something up out of something they've read somewhere. It sounds plausible, and is expressed with great confidence, but it may be absolute balderdash.

[Geoffrey Ellis]

That's the thing about chat-bots. When they don't know the answer (and really, they never "know" any answer), they make something up out of something they've read somewhere. It sounds plausible, and is expressed with great confidence, but it may be absolute balderdash.

Never trust a chat-bot. And furthermore, what the hell is a chat-bot?? I've never heard of one before reading this thread. But based upon what I've heard so far, they are not inspiring a lot of confidence.

[paddler]

That's the thing about chat-bots. When they don't know the answer (and really, they never "know" any answer), they make something up out of something they've read somewhere. It sounds plausible, and is expressed with great confidence, but it may be absolute balderdash.

Never trust a chat-bot. And furthermore, what the hell is a chat-bot?? I've never heard of one before reading this thread. But based upon what I've heard so far, they are not inspiring a lot of confidence.

Indeed! But how do we know you are not a chat-bot, Geoffrey?

Alan Turing wrote a nice paper about this problem almost 75 years ago. For a quick summary, read about The Turing Test.
We are finally approaching the point where the behavior of machines and humans is getting very difficult to distinguish, and in part for the very reason that Tunborough stated!
I enjoyed Tunborough's summary, in part because it is true, and in part because it is a very good description of the behavior of some people I have encountered.

[david_h]

We are finally approaching the point where the behavior of machines and humans is getting very difficult to distinguish, and in part for the very reason that Tunborough stated!

Depends on the context. We can ask the posters in this discussion to explain what they say, why they think that way and give references to other sources of information. If a chat-bot would do that it would be more convincing - and more useful.

On the topic. My Burns flute is also harder to play in the third octave that my antique Metzler. But the antique with the Burns head on it is not that different to how it is with its own head. So maybe the difference is in the body rather than the blow-hole cut.

[Tunborough]

I enjoyed Tunborough's summary, in part because it is true, and in part because it is a very good description of the behavior of some people I have encountered.

Ah, yes, that crossed my mind when I was writing that. We are all capable of it. NPR did an episode of This American Life a couple of decades ago on the dangers of having a not quite enough knowledge. https://www.thisamericanlife.org/293/a- ... -knowledge

[waltsweet]

Steve,

I'm in the throes of designing my new Bb drumcorps fife, EMMETT model. The tuning issues are slowly resolving.

Simplified rule: The more taper (greater taper rate, more inch-per-inch), the greater stretch of the octaves. I avoid saying "the top octave is flat." Boehm's curvilinear* ("parabol-ish") head worked by lowering the octaves progressively. Of course, this mod did the job. Analogy: when I'm setting-up my lathe to cut a tapered profile, I must first set the relationship of beginning-to-end (the overall taper), then I adjust the basic diameter. So in acoustic design, it's important to address the overall relationships first (and to rephrase the problem). The rule about increased taper rate is supported by Rayleigh's Rules.

Taper rate (in the body) is one way to adjust the octaves. Another is the endstopper position: moving closer to the blowhole will stretch the octaves progressively. It seems these parameters comprise two ways to do the same job, but it's not quite that simple. I have found that the endstopper position has a great influence on the ease of producing the notes in the third octave. These high notes need to be available under normal circumstances as enhancements to the lowest notes. The low notes need the highs as upper partials; without them, the lows lack complex character, the flute lacks tonal flexibility. I have played flutes that can't get the basic high notes (G3, A3), and such flutes are lacking in playability (even when the low notes pass muster on the tuning machine). By making incremental adjustments, a serviceable position can be found for the endstopper.

The notes G3 and A3 are basic "anchor" notes. Sure, you want a flute that can play all the notes in between, but for Gestalt, I think we need to find endstopper position, length and rate of taper 12-24, length and rate of taper 0-12, in that protocol. From there, you can look for complex fingerings in the third octave. About the 12-24 bore: making it smaller will raise the third octave slightly, lower the second somewhat, and raise the first octave quite a bit (supported by Rayleigh's Rules).

You mentioned the fingerings based on the second (fourth) and third harmonics. The principle is easily seen on the fingerings for Boehmflutes. For example, to play F#3, we open the F#-tonehole (to sound its 4th harmonic = F#3) and at the same time, open the B-tonehole (to sound its 3rd harmonic, also = F#3). However, we have to be careful on the diatonic flute because most holes take a step of two semitones. To do so, we make the holes smaller and higher up the bore from Boehm's Acoustically Correct Position; the B-tonehole especially will pull the pitch too high. The problem is verified on the drumcorps fife: To play F#3, we open hole #2 (B); the output is 40 cents sharp because the B-tonehole is too high. To play G3, we open hole #2 as before; but in this case, output pitch is OK because the proportions have changed and hole #2 is not too high up the bore now. I don't know if your chat-bot has been programmed to think in these terms.

*In Die Flöte und das Flötenspiel, Boehm only said it resembled a parabola, but so do many curves. He never said it was mathematically a parabola (a paraboloid); the math nerds must have hijacked this notion. My next trip to the soap-box will discuss Boyle's Law -itis.

Walt Sweet

[Terry McGee]

Agreed, Walt, Boehm only said resembled. It was Richard Carte who went totally overboard on the topic in a sales puff-piece promoting his flutes. My favourite:

"The parabola-head-joint seems to effect that for propagating sound, which the parabolic reflector does for propagating light. The vibrations are concentrated in, and propelled from the one, as the rays of light are concentrated in, and transmitted from the other, both with superior velocity and power."

So the mighty parabola not only makes lights brighter and sounds louder, but faster as well. And I thought the Speed of Light and the Speed of Sound were pretty much regarded as constants, well before Boehm and Carte!