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ttonon

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  1. I suggest pure ammonia. It's very effective at dissolving grease and grime. More eco-friendly cleaners are those containing orange oil, like Go Jo and others, but I don't think these are as potent.
  2. Stephen, thanks for the info, but this is really not directly related to free reeds. The chanter of bagpipes in Western Europe are double reeded, and thus resemble oboes and bassoons. I understand that in other countries they are single reeded, like clarinets. But in all cases, they are beating reeds and not free reeds. I'm sure many here know that beating reeds regulate the pressure pulses to a vibrating air column, and the acoustic vibration modes of this air column are what produce the musical tone. That's why the speed of sound is a relevant parameter in the tuning of these instruments. Such is not the case with western free reeds, whose sound source is the vibrating cantilever of the reed tongue, and this vibration doesn't on the vibrations of an air column. With the Asian (symmetric) free reeds, however, there is an acoustic coupling between the reed and an air column, so there, the speed of sound is relevant. The effects of temperature on western (unsymmetric) free reeds, however, is thus an entirely different effect than the effects of temperature on the vibrating air columns of woodwinds and Asian free reed instruments. Best regards, Tom
  3. Hi Wally, in my latter years, I've become more direct and to the point. I wasn't always so, but I find it to be the best overall approach because when I become too concerned with how people choose to react to my writing, I waste a lot of time. I've learned that people who say they are "belittled" by others are most often choosing to feel belittled, and they are motivated for that. Most often it's because they have no factual or rational defense, and so attacking the other person is the only way they can keep asserting their erroneous position. So why do you choose to feel belittled? I had no intention of belittling you. I addressed only what you wrote, not you personally, and even you (now) acknowledge that you made errors in what you wrote. So why condemn me for pointing out your errors, your incompleteness, and the unusual physical theories you put forth, and still do put forth? (By the way, you can't belittle me because I know who I am.) Have you noticed that people who claim to be belittled accuse the other person of behaving in the displeasing way they themselves are behaving? Your comment about me poisoning the group is a good example. It's you who is poisoning the group with your language and with your attack on me. It seems you want this group to be poisoned, because when it is, you believe most everyone will see me as the miscreant. I think you're probably wrong. When people correct me for my erroneous thinking, I usually thank them. You can look through this thread for proof of that. Why do you choose instead to throw a tantrum? Why are you asserting that you cannot make any error regarding the laws of physics, at the same time you're denying any reference to physics? This is childish behavior. I ask you this because I still have hopes you can reconnect with your inner self who happens to be a well-meaning, adult human being. I think you just lost sight of that. Best regards, Tom
  4. Sorry, I hate to drive home the point, but virtually all people who say they are basing their observation on experience provide at least a semblance of a physical theory to support their claim. Wally is one example. He reports his observation that variations of pitch occur with changes in humidity. That's fine, in itself and I have no objections to it. But he goes far beyond that when he asserts his theory that the swelling of the wood because of changes in humidity causes changes in clamping pressure on the reed assembly, and that's what causes changes in tuning. It's comical, like shooting at someone in the dark. He says he doesn't want to get into the science of it all but expects us to accept his scientific theory on why he observes what he does. Wally, let me ask, why don't you just state your observation and leave it to more technically competent posters to devise a physical explanation?
  5. Wally, when you say you will "stay away" from the math, physics, etc., then make a statement about what you think the physical quantity "pressure" has on another physical quantity, "frequency," with a trail of invoking other physical concepts such as "humidity" and "air density," you're contradicting yourself. In your mind you have a physical theory, even if you don't recognize it as a physical theory. Thus, you are not "staying away" at all. In my view, your theory is not only incomplete, but also erroneous. Try making your theory more complete, and I might listen more to you. Best regards, Tom
  6. No, but it's helpful. Your abscissa incorporates the idea that octaves are equal intervals, by perception, and that's correct. The distance between each of the "A's" is the same. I was visualizing the axis with frequency as the variable, which would erroneously stretch out where the "A's" occur, resulting in a straight line. Thanks for the example.
  7. Hi John, I agree with your correction. I'll change my post to read, "... overtones, or partials, often in whole number ratios of a fundamental, in which case they are called harmonics." In Physical Acoustics, these terms have specific meaning. The overtones of a tone generator are generally not harmonics, but with instruments that have sustained tones, such as woodwinds, bowed instruments, and free reeds, we don't hear the full overtones and the upper components of the waveform we do hear, called partials, are harmonic. They must be harmonic because the forcing function of these instruments is periodic, which requires that the musical tone and all its partials be exactly periodic. When these instruments are played, a cooperation among all overtones is achieved, whereby only the value of the overtone at the harmonic frequency is utilized. We don't hear the rest of the overtone. With instruments that produce transient sounds, as with struck or plucked instruments such as pianos, guitars, xylophones, bells, etc., there are no time constraints, and the tone generator is allowed to sound all its overtones, which mostly are not strict harmonics, though they are tuned so that the non-harmonicity doesn't sound more like noise. But even some instruments, such as cymbals and drums, do produce a kind of pleasing noise when used in the right place. The sounds from all these instruments are interesting and pleasing, much because of these nonharmonic features. But it's often quite a chore to tune bells and bars so that their overtones provide a pleasant musical tone when we hear them as upper partials. With strings, there isn't much of an issue with such tuning, and the stretched overtones we hear (because of stiffness) are most appealing and advantageous in providing us with music. But of course, proper string design eliminates too much stiffness, which would lead to such overtone issues. For instance, as you make a string more stiff or thick, it soon becomes a bar.
  8. Hi Dave, you're right. I remember this now but it was so long ago. Pitch is subjective and is a way of ordering tones along a musical scale, not something amenable to numbers and based on fundamental physics, as is frequency. As a small correction, the argument of the log function in your formula should be F/Fo, where Fo is the starting frequency. The idea of F = 0 as a starting frequency isn't sound (pun intended). I also point out that when we add notes with each half tone, we are actually adding frequencies that are multiples of 1.0595 times the frequency of the previous note. The frequencies are not being added. If that were true, each frequency would be the previous frequency plus a DeltaF constant throughout the octave. The "human part" of this is in our feeling that each half tone added is "equal" interval as all other added notes, as in "equal temperament." An interesting experiment would be to have a person with perfect pitch identify the note he hears, of frequencies say from the low end of the piano to the top. Let's say his perfect hearing is perfect. I believe he'd do very well if he hears pure sine waves. Let's then plot his response, using a dot in a graph with both abscissa and ordinate as double axes, one for frequency and the other for "note." If you plot this, I'm sure you'd get a linear, straight line. If a real piano is used, there would probably be more scatter. But there would be no meaning to the locations between the dots. The above picture is what I was visualizing when I made my previous comments. But my error in looking at it this way is that pitch is not a numerical quantity with which you add octaves one on another. It's just notes, or categories. Regardless, thanks for catching that and helping me to understand it better.
  9. Exactly. It is 12 semitones higher. Additive, not multiplicative. What note above middle "A" is twice the pitch of middle "A."
  10. Sorry. Forgive me for my unnecessary elaboration. But yes, Peterson was a clever dude and was able to exploit the idea in applications that never saw it before. I bought the 490 Tuner about 20 years ago and now it's worth twice the price. The rotation speed of the disc, which is set according to their stable oscillator, differs for different ranges of frequencies, as you might expect, with the higher frequencies requiring faster rotations. The company then went a step further, with the iStroboSoft, used on ipads and computers, which doesn't have a mechanically rotating disc, but I believe LCD's are sequentially illuminated by updating the screen at the correct rate. It makes it look like there's something rotating, and the speed of that rotation is again set by the oscillator, with the strobe light determined by the musical instrument. At least that's how I think it works.
  11. Dave, sorry but I don't understand your last equation. Question: If your concertina is tuned to A 440, that means that the octave A above it is 880. Correct? Are you saying that the second note is not twice the pitch of the first note?
  12. Richard, I'm surprised that you haven't heard of the several applications of strobe lighting. There's a strobe instrument that can very accurately measure the speed of a rotating part. It's flawless and simple. You just change the frequency of the strobe until you see the part freeze in view. It can measure deviations from a mean, etc. Strobe techniques were used when they first figured out how different animals pace. You take a series of photographs of an animal walking or running in dim light, using a bright flash in a strobe. People were able to see very clearly the different kinds of gates horses and most other animals use. Until then, no human had a fast enough response to see the sequence of steps in a full gallop. People also learned much about how high speed projectiles penetrate targets. With the very high frequencies available, you can stop a bullet, then see it a mm later in its path and measure how fast debris is flying away. I believe the man most associated with it was Harold Edgerton, in 1931. His bulb is a discharge bulb, mostly powered by a large bank of capacitors, with responses in nanoseconds. The flash speed is normally so short, you need an inductor to slow down the discharge of the capacitors to expose the film, or CCD. I know because although some else in my company brought the idea into the company, I built a strobe system to measure the power of solar cells. They can illuminate the entire area of the cells with one-sun intensity, over a period long enough to electronically scan the terminal voltage from negative to greater than open circuit voltage over varying load and get the power curve. Edgerton was a good guy. I read he made all his patents free so that German and Japanese photo industries could rebuild themselves after WWII. I see the calculation you made and thanks for the correction. I failed to raise the number 2 to the appropriate power. Silly me. These results hold throughout the musical range. Best regards, Tom
  13. Dave, thanks for the comment and opportunity to clear up this issue. It can be confusing. The pitch of a musical tone is the frequency we perceive. Although it doesn't make sense to say so, it may be instructive to view frequency as what a tuning instrument "perceives." It works by physical principles. Our brains work by who knows what? Perception belongs to humans and frequency belongs to an objective nature, if we can call it that. Musical tones from real instruments contain multiple frequencies, called overtones, or partials, often with whole number ratios to a fundamental and in which case they are called harmonics. This is physics, Mother Nature. When we hear a musical tone, we perceive the fundamental frequency of the (mathematical) Fourier Series that represents the actual tone and call it the musical pitch. This is mathematics, and miraculously, it's also nature, as our brain/ear system perceives. There usually isn't any difference in the pitch we perceive and this mathematical fundamental. But if the tone is so heavily laden by upper partials, we progressively fail to detect the correct fundamental, to the point that we wouldn't call it a musical tone. We'd then call it noise. Thus the relationship between pitch and frequency is quite exact, but maybe not perfect. Your mention of the term "logarithmic" indicates you are confusing volume with loudness. Loudness, a perceived quantity, has a logarithmic dependence on volume, which is the physical measure of acoustic power per unit surface area. Loudness belongs to humans and volume belongs to nature. "Adding pitch multiplies frequency." I understand what you mean, but it's not an edifying description. Yes, each semitone is the 12th root of 2 multiplied by the preceding note. [Each upper half tone = (Start.Freq)*(2^1/12)]. That means when you multiply the root frequency in succession 12 times, you must arrive at twice the original value; i.e., (Orig.Freq)*[2^(1/12)]^12 = (Orig.Freq)*2. The cents definition is similar, and with the same geometric definition. Thus when you multiply the root by 2^(1/1200) you get one cent more frequency and for the entire octave, (Orig.Freq)*[2^(1/1200)]^1200, you again get (Orig.Freq)*2. This arises from the definitions of an octave (factor of 2), the division of the octave into 12 tones, and the definion of a cent being 1/100 of the tone interval. You might notice that your multiplication facto 1.059 = 2^1/12. I believe you call this logarithmic because the geometric operation means you add exponents and closed form solutions to cents calculations require logarithms.
  14. Richard, how did you determine that 0.1 cent is about 58 ppm? With the musical convention, an octave is broken into 12 tones, with each tone broken into 100 cents. There are thus 100 cents between each semitone. The question is, what are we measuring? Isn't it ultimately frequency? Thus, by its definition, one cent is 1/100 of the frequency interval between semitones and 0.1 cent is 1/1000 of the interval, or one part in a thousand. You can go to online calculators if you want to very that. Such a result applies along the whole range of musical pitch. The reason Peterson uses the strobe method is because it's so simple and foolproof, as long as you have a good frequency reference. The idea of strobe measurement goes back a hundred years, and for the Peterson instruments, an oscillator is used to accurately set the rotation speed of a wheel with markings. The signal from the musical instrument is used to strobe a light onto the rotating wheel. This will make the correct markings on the wheel appear stationary, and the circumferential distance from the zero along with the known speed of rotation tells you the frequency of the input signal. Here's from the manual of a Peterson 450 strobe tuner, which I have: - - - ACCURACY The exceptional accuracy of the PETERSON STROBE TUNER, MODEL 450 is due to the fact that all of the pitches are controlled by a single oscillator circuit of unusual design (patented) using components of the highest stability. The pitch is not affected by changes in power line voltage and the temperament is derived from precision counting circuits that are not subject to drift or variation. Recalibration should not be attempted in the field if an accurate standard is not available. Tuning forks can vary greatly depending on quality, temperature and humidity. Do not rely on these except for relative measurements. - - - From the manual of the iStroboSoft: - - - Calibrating iStroboSoftâ„¢ iStroboSoft will measure and display to within 0.1 cent accuracy throughout its full range. However, there may be instances when measurements do not match when compared to an external tuner. In such a case, the external tuner may be inaccurate, or iStroboSoft may be subject to biasing introduced by an inaccurate reference clock in its host device. This inaccurate reference clock inserts a 'bias' onto the audio signal during processing. This bias can be enough to sway an otherwise accurate measurement by as much as +/- 3 cents! To allow these host devices to be used to accurately tune instruments, iStroboSoft has a calibration feature which will independently allow it to calibrate to an external audio source and measure the offset of the bias to ensure an optimal measurement. This calibration is remembered permanently until you remove it. - - - There are calibration notes for Steve and others who use this software. - - - RAc, why end the discussion when it continues to bring forth all kinds of insights? Thanks for clarifying your position and I take it to mean you have no objections to my technical comments and that they were justified. Best regards, Tom
  15. RAC, you're right, there is confusion. I myself made the mistake of thinking that Steve's tuner was a dedicated instrument and not a software concoction in an iPad. My apologies there. On the other hand, Alex does say, "Oscillators are affected slightly by temperature changes though. Very accurate laboratory frequency references place the oscillator inside a thermostatically controlled oven." Thus, he was definitely talking about hardware, which justifies my comments. Then again, you say, "From my understanding, everything realized in software - no matter what algrithm they implement - must use the underlying hardware for reference." This also justifies my comments. So it seems there's confusion among all of us. I agree with your suggestion to have people conduct experiments and hopefully they will be done with enough rigor and explanation. Best regards, Tom
  16. RAC, thanks for your impressions on my evaluation of Alex's suggestion, though your technical argument is not applicable to devices like Peterson strobe tuners. I do agree that if Alex chooses so, he can be offended by my claim his suggestion could be a "little knowledge can be a bad thing." That would be his problem. But it seems you yourself chose to be offended. Am I right? We all know of many such examples where people extrapolate true knowledge to erroneous belief, and I made that comment not just for Alex but to all of us who might benefit from the reminder. The web seems to invite such behavior from all of us. And where are your relevant facts? You recite a convoluted story that doesn't explain all the key details necessary to make a scientific assessment of your conclusions, or part conclusions, or "sort of" conclusions, whatever conclusions. Then you extrapolate that into an argument why a Peterson strobe tuner could be inaccurate. Here are the relevant facts: Electronic timing circuits are based on two technologies: RC circuits or crystals. (We also have atomic clocks, but we need not let that confuse us.) Resistors, capacitors, and crystals have strict specifications, according to the class they are assigned to, and that determines their cost. I repeat, do some homework, and find that both resistors and capacitors in IC circuits have temperature coefficients varying from zero to somewhat less than 100 ppm/C, over very wide temperature ranges, and crystal oscillators, depending on the crystal cut, vary from zero to up over 100 ppm/C. That's for the components themselves. Then add to it the facts that compensation circuits can eliminate any significant temperature effect and that typical room temperature variations are only a small fraction of the specification ranges, there's no reason whatsoever to blame the magnitude of the variations people see in tuning free reeds in their own homes. Unless of course they're using a faulty meter or some kind of homemade method to make the measurement. I repeat, Peterson strobe tuners are accurate to within 0.1 cent, which is the smallest unit measured for musical pitch, and - no offense - I trust their engineers more than I trust you with your example. I've read that the top musical schools claim that most people can discern musical tones to within +/- 10 cents. I'd be surprised if people with perfect pitch could detect differences down to 0.1 cents. If I'm wrong, that would be a good example of a "little knowledge can be a bad thing." We do it all the time. I appreciate the comments you and Richard made regarding ways to test cell phone and computer circuits, and I have no idea how much software is integral to their mechanisms for measuring this. I encourage you to do such experiments. My comments here are restricted to devices with dedicated designs to measure musical pitch and sold with that in mind. Because of my arguments here, I think it not too likely that even cell phone or computer methods could result in the errors mentioned at the beginning of this thread, unless their designs are incompetent. But I could be wrong and would welcome correction. A word on offense. If I told you, "You have a funny nose," and if you never thought about your nose in such a way, you'd either be curious or think I'm a nut. But if you had a history of people discussing your nose and you looking in the mirror with misgivings, you might choose to be offended by my statement. So, if Alex isn't offended by my comment, he's thinking intelligently, understands why I said it, and takes no offense. If he chooses to be offended, he thinks I speak the truth. Thanks for your good wishes, Tom
  17. Hi David, thanks. But I wonder, why would a person with perfect pitch be annoyed by a piano that's tuned to a different standard than the world's orchestras? As long as the piano is tuned within itself, why would it matter, especially since the standardized pitch of middle A is a convention? With my hearing loss, it's interesting that Paul Simon made the same announcement, that he lost all hearing in his left ear, within days of when it happened to me. I read that doctors have labelled it "Sudden hearing loss," with no explanation of why it happens. However, I did abuse my ears when I worked as a carpenter in the early 1980's. Especially my left ear, when I put my head very close to the circular saw, in order to cut on the pencil line. I sometimes asked, "Do you want the cut on the left, the right, or the middle of the line?" Stupid me. But after a month or so, it hit me like a ton of bricks that I was probably damaging my ears, then started stuffing my ears with things, in the days before all the warnings and devices for hearing protection. I remember one time, when I was hammering in roofing nails. I stopped to stuff my ears with pieces of a plastic bag and the boss walked by, saying, "Oh Tom, don't worry about those small hairs. They eventually break and you won't need to worry about it. But it's curious that it took decades for the final collapse. My question is, why such a complete collapse of all frequencies? Any noise has a spectrum of intensity, and so I'd think that some frequencies would still respond. It may be that the saws, the hammers, and other noises together covered the full frequency width. Best, To,
  18. Thanks for that interesting perspective and I believe there's much truth to it. Of course, there are people fortunate enough to have perfect pitch, either absolute or relative, but that doesn't detract much from your statement. In addition, as we age, our hearing generally deteriorates, sometimes severely. I in fact went through a tragedy by suddenly losing all my hearing in my left ear and about half my hearing in my right ear. It happened in two stages, over only a couple of weeks. I can't explain here all the complex consequences to such an event, but my musical performances suffered severely, and I even stopped playing with others in small groups or even going to local concerts. That happened about 10 weeks ago, and I've adjusted somewhat, but basically, I'm extremely grateful for the half ear I have left and shudder to think about my losing even that. I mention it here only to point out the many real issues we humans are involved with and sometimes we can get lost on issues that are of little importance. I also want to mention that a few years ago, when I still had decent hearing, I noticed that I'd perceive a certain pitch to a musical tone with my "good" ear, and a slightly different pitch with my "bad" ear. This is just another interesting part of this effort to tune musical instruments to the "right" pitch.
  19. Alex, upon reading this thread again, I'd like to say that I don't think there's much basis for your suggestion. Of course, no reference is perfect, but I think you're not realistic, in an example of a "little knowledge can be a bad thing." Do you realize that resistors, capacitors, inductors, etc. have temperature coefficients measured in parts per million per degree C? Even a lousy crystal oscillator measures at the worst a part in ten thousand. You need to realize that a primary criterion for a good reference is temperature stability. That's why they are called "references." They are chosen such that the fluctuations resulting from normal use are not noticeable. I don't think Peterson could advertise 0.1 cent accuracy if their measurements would noticeably fluctuate with relatively minor room temperature variations, as is the case here. Maybe you'd like to search out the temperature coefficients of resistors, capacitors, inductors, etc. used in printed board circuitry and get back to us. Google is our friend who can keep us real. Best regards, Tom
  20. Luke, that's quite an accomplishment. Thanks. My interest in concertinas is mainly theoretical and it gives me a good reference. I see you allow the user to edit the layouts, then save the edit. What does the edit effect, the layout on the website that you made or a layout that's private to the user? My feeling is that you don't want the public to make permanent changes to your website. I do suggest that you add a row just below the piano keyboard that gives the frequencies of the notes, for equal temperament. It might have to be a double row to include all the white and black keys. A format with one decimal place resolution would be fine. Such a row would help much with theoretical discussions. In any event, congratulations on a wonderful contribution. Best, Tom
  21. Steve, before you replace the leathers, I'd get expert advice on how to go about it. If I'm not mistaken, the leathers of bandoneons must act in ways different from those of concertinas and accordions. The tremendous dynamics in the music, especially when the weight of the instrument is slammed onto the lap, are not present in the music of other free reed instruments, and so the leathers of the bandoneon are installed differently because of that. At the same time, I'm not certain of all this, and I was never able to talk to an expert about it. Best regards, Tom www.bluesbox.biz
  22. Hi Steve, according to my calculation for the frequency of the first transverse mode vibration of a cantilever, and assuming a steel tongue, changing temperature from 19 degrees to 13 degrees would increase the pitch by only 0.24 cents. Your experiment gives a minimum of 0.4 cents change, which isn't too far off, and I'd attribute the difference between your result and mine to the impreciseness of your temperature and pitch measurements. I think we'd both conclude that the 1.2/1.5 cents discrepancy you originally measured (assuming these were accurate) may be due to things other than temperature. Can the difference be due to barometric changes? Well, let's see. Barometric pressure at sea level can easily change from about 29.5 to 30.5 mm mercury, or about 3.4%. Because of the ideal gas law at constant temperature, that's also the percent change in density. The pitch of free reed vibration depends on air density because the driving force is the kinetic energy of the air that gets intermittently stopped when airflow passing through the slot is suddenly stopped. The kinetic energy of air is = (rho*V^2)/2, so a percent change in rho is a percent change in kinetic energy. The relation between air density and pitch is complicated, but if we're talking about something like one percent changes, one percent of a frequency change would be from 440 to about 436, or about 16 cents. That's of course way too large, but intuitively, it tells me that yes, barometric effects on pitch can possibly explain much of the original pitch difference. Maybe you'd want to verify this by recording pitch measurements along with accurate barometric measurements. Best regards, Tom www.bluesbox.biz
  23. How do you know what the comparison between the dynamic forces and the magnetic attachment forces on a piece of magnet will be? We do know that if the magnetic pieces are small enough, their magnetic forces are more than enough to keep them on the tongue. As Alex mentioned, there can accumulate a magnet fur on a tongue that stays there during vibration. My guess is that the ratio of dynamic force to magnetic force increases as the size of the magnetic particle increases, because the dynamic forces scale with volume/mass and the magnetic force scales with surface area contact to the tongue. But this doesn't say anything about whether a given magnetic piece can cause a desirable change in pitch and still remain on the tongue. Here, we need to experiment. I don't know if it's really a billionth of a gram as you suggest, but it may not be too difficult to put the magnet back in the same place, if you check the pitch with a test run. I'm not clear on what you mean by "stop or shed its weight." But I do see perhaps a complication if the magnet is placed in a different place off center on its short dimension. The possibility of slightly exciting torsional modes might complicate matters. My gut feeling however is that such torsional vibrations aren't much of a threat. Again, all we have to do is experiment. Best, Tom
  24. https://turboharp.com/collections/the-turboslide-series
  25. If you're interested in a theoretical explanation of this, I believe it's because at those high frequencies, resonances of the chamber interfere with the self excitation mechanism that makes vibration of the reed tongue possible. The resonance can result from the cavity acting like a Helmholtz resonator or a quarter wave tube. You can read more detail at https://concertina.org/pica-volume-2-2005/reed-cavity-design-and-resonance/ Best regards, Tom www.bluesbox.biz
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