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09 Mar 06 - 10:29 AM (#1689209) Subject: notes hidden in chords From: GUEST,leeneia It appears that sometimes when you play a chord, that there is a fourth note "hidden" in the chord. My husband gave me an explanation for this, but I can't remember how the explanation went, exactly. If anybody can tell me what chords contain what hidden notes, I would appreciate it. The knowledge may come in handy when playing my dulcimer. |
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09 Mar 06 - 12:38 PM (#1689335) Subject: RE: notes hidden in chords From: GUEST Barbershop Quartets and other singing groups that hold chords, are aware of an extra voice that appears when the voices are all on pitch. It sounds like is a high note that is a common harmonic to all the notes that are being sung-- It is, more or less an illusion--every note has a series of harmonic overtones that sounds above it at the same time--when the voices in a group are on pitch, and they sing a chord, some of these harmonic overtones blend, as well, and they create the feeling of an extra voice. On a dulcimer, you can sound harmonics on each of the strings by damping the strings at the exact midpoint of the neck, and striking the strings. These notes are all sounding when the strings sound, but the fundamental note that the string plays overpowers them-- |
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09 Mar 06 - 02:37 PM (#1689418) Subject: RE: notes hidden in chords From: Peace I think the answer is here. I too hear another note in certain chordings. |
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09 Mar 06 - 05:17 PM (#1689512) Subject: RE: notes hidden in chords From: Bee-dubya-ell The Mammas and the Pappas frequently spoke of an extra voice they nicknamed "Harvey" that seemed to materialize when their vocal harmonies were perfectly in synch. |
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09 Mar 06 - 05:25 PM (#1689522) Subject: RE: notes hidden in chords From: GUEST,DocTom Hi people: The explanation you may have originally been given goes: - They're called resultant notes. There's a high one which coincides with the sum of the frequencies of two notes, and another which is the difference between the frequencies of two notes. Very often they can't be heard because the resultant frequency is too high or too low to be audible. Try asking organists about resultant notes - they frquently get them. Of course, when you get more than two notes, the possibilities multiply!! |
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09 Mar 06 - 05:32 PM (#1689527) Subject: RE: notes hidden in chords From: Peace So that orchestra I've been hearing may not be just in my head? |
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09 Mar 06 - 05:33 PM (#1689529) Subject: RE: notes hidden in chords From: Stewart That is true when the chords are sung or played in an untempered scaled. That is, when the intervals between notes in the chord have simple ratios to each other. For example, in the untempered scale the notes of a major third have a ratio of 5/4 (386 cents difference) and the two notes share the most harmonic frequencies. In the tempered scale a major third has a ratio of 1.26 (400 cents difference). Instead of getting a lot of harmonics, you get beats due to slight dissonances. That is the secret of barbershop harmonies. Instruments that are tuned to a tempered scale can achieve the same effect if the musicians bend their pitches to a tempered scale on sustained chords. See HERE Cheers, S. in Seattle |
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09 Mar 06 - 06:38 PM (#1689571) Subject: RE: notes hidden in chords From: JohnInKansas The real "hair of your legs" chord that Barber Shoppers strive for is not due to producing a higher harmonic. Its the tonic, or tonic octave note below that results when a full chord is sung in close harmony. The notes sung can be any 3 distinct notes of the chord, and the match must be in "just tuning" and quite accurate; and it does make the singers feel like something is crawling through the hair on their legs. Members of the listening audience have been known to feel the urge to "scratch something." There has been much debate about whether such a note really does occur physically, and simple Fourier analyses can be produced to "prove" that it can't really happen; however it can be shown that if the "sung" tones are in accurate just harmony, and especially if the "sung" tones have rich harmonic content, and if there is nonlinearity in the participating resonances it is possible to produce "subharmonics" - below any note produced by any of the singers - and it is these notes that produce the effect. The "proof" was developed as a dropout result from analyses of radar signal processing techniques, and while it requires only "slightly advanced mathematics" it's extremely tedious. It's a proof that if nonlinear effects are included, subharmonics can occur as physically real phenomena. It doesn't prove that nonlinearity has to be present, but thus far no one has demonstrated a way for "purely linear" systems to generate such tones. When it does happen, it is common for additional "internal tones" within and above the range of the singers to be present as well, and to be heard, but it's the low tone subharmonic that's the characteristic of the effect. The "appearance" of extra tones not deliberately played, within and above the octave of the deliberately sounded notes is relatively easily explained with linear Fourier thinking. It makes little difference what chord, or what parts of a chord, one plays. Both physical (real) tones are known, and there are "psychologically perceived" tones that some people hear. There probably are physical explanations for the "all in your head" ones, and for cases that have been studied the nonlinearity of the hearing sytem (ear canal, nerve responses, etc) sometimes is needed for demonstrating that there is a physical presence of the tone that a particular person "hears." In other cases it appears to be that your mind supplies what "should be there" when something is missing in a well known percieved phenomenon. You can enjoy them without worrying about it (usually). All such effects are more common with just tuning, and the almost universal use of equi-tempered tunings makes them less likely to be heard with any real frequency, but even in equal tempered tunings the notes get close enough sometimes. Since playing the wrong chord just to get the effect is counterproductive, the satisfaction of knowing that (mostly) they're not just something imaginary should allow you to enjoy them when they happen, without a lot of analysis. There are no particular chords that produce the common effect better than any other chord. It depends largely on the notes being played being in tune (just tuning) with fairly good accuracy. Certain instruments may tend to produce this effect for particular chords, but this may change from day to day if the instrument is retuned. If you want to experience the "ghost tones" in rich profusion, you'll need to play a just-tuned organ, join a string quartet, or sing Barbershop. (A saxophone quartet can do the Barbershop chord if the members concentrate on it, although it's nearly impossible with clarinets. Other instruments vary. Most plucked string instruments lack the necessary sustain and frequency stability over the short duration of the notes, both of which are necessary for the most "thrilling" effects.) John |
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09 Mar 06 - 06:54 PM (#1689576) Subject: RE: notes hidden in chords From: Peace I have been working on some songs with my guitar tuned to an E chord. I am clearly hearing another note when I play certain configurations. The note fits, but it sounds a bit like I have a seven-string guitar. Nice to know why. Thanks all. |
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09 Mar 06 - 07:11 PM (#1689580) Subject: RE: notes hidden in chords From: Bert All these answers seem rathe complex. Are you sure it's not just a beat frequency generated by the harmonics? |
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09 Mar 06 - 08:06 PM (#1689635) Subject: RE: notes hidden in chords From: JohnInKansas Bert - Some beat frequencies are easily heard, but with the exception of the difference frequency some people like to use for tuning, most of the simple beats that are easily produced are either not "nicely" related to the tones being played or are too high to be heard. The ghost tones are very similar to simple beats, but require a little more complex explanation, which unfortunately is complex enough to be difficult to relate briefly. It's not really inaccurate to describe them as "just beats," but it's not a complete explanation. The "explanations" generally incorporate seemingly endless tables of all the frequencies, and all the differences between all the frequencies, and all the ratios of all the frequencies... A bit like trying to explain "how many words can be spelled with the alphabet," giving examples of them all. One of the best fairly complete explanations of all of this still is probably Helmholtz's On the Sensations of Tone, which was published in the 1870s(?). An English translation, the second edition of the English version of the fourth edition of the original German - or something like that, is available from Dover fairly inexpensively. If you're a musician, I can almost guarantee that you won't read the whole thing; but if you look through it intelligently, without getting bogged down in the details, you may be able to extract some satisfying understanding of what interests you. There are several other references that include pretty fair explanations, although most of the popular ones that I've seen are a bit superficial. While the explanations and examples given are generally accurate enough, they may easily lead one to draw incorrect insights when applied to different situations than the ones specifically given in the books. There are a few places where you can find "rules of thumb" that might be helpful. Some of these just give the rules. The ones who try to explain them are usually either superficial or just plain wrong, although the rules do work - sometimes - for predicting when the ghosts may appear. I don't have one of these sources "remembered" to refer you to one of them. John |