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undertone_series [2023/01/05 13:11] – [Methods to play an undertone series] mete | undertone_series [2023/01/05 13:56] (current) – [Methods to play an undertone series] mete | ||
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- | The Undertone series, also commonly called the subharmonic series is a series of pitches with mathematical relationships to one another that are a naturally occurring sequence the can be represented by divisions or additions | + | The Undertone series, also commonly called the subharmonic series is a series of pitches with mathematical relationships to one another that are a naturally occurring sequence the can be represented by divisions or multiplications |
====Methods to play an undertone series==== | ====Methods to play an undertone series==== | ||
===Acute bowed force, as to interrupt the natural vibration of a material=== | ===Acute bowed force, as to interrupt the natural vibration of a material=== | ||
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+ | ==On strings== | ||
This is only possible on instruments with large wound strings that are very long such as the cello and double bass. The method involves bowing the string strongly, in such a manner that causes the string to vibrate as though it had a longer overall length than is typical, shifting pitch following the undertone series as the firmness of the bowing is increased. This type of bowing should be considered a form of [[regulation]]. Typically the three notes in the series can be generated on a bowed contrabass | This is only possible on instruments with large wound strings that are very long such as the cello and double bass. The method involves bowing the string strongly, in such a manner that causes the string to vibrate as though it had a longer overall length than is typical, shifting pitch following the undertone series as the firmness of the bowing is increased. This type of bowing should be considered a form of [[regulation]]. Typically the three notes in the series can be generated on a bowed contrabass | ||
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+ | ==on Lamells== | ||
+ | The only example of this phenomena can be seen on is the terpodion, which is bowed lamellaphone that bows tongues with large flat pads at the ends on each tongue. The tongues are bowed against a rosined cylinder by the force of the tongues attempting to return to a resting position which is at tension against the cylinder, and when the cylinder spins the tongues are moved transversely and repeat the process based off the degree of mass at the end of the tongue. Much like the action of forced vibration on corrugated surfaces these tongues may not always return to position at the resonate pitch, and with the correct regulation the tongues can play an undertone or an overtone of the original pitch. | ||
+ | {{https:// | ||
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+ | ===Forced vibration instruments=== | ||
+ | On instruments that use forced vibration or corrugation the undertone series can be produced by allowing a plectrum to ' | ||
===Reduction of air on invert reeds=== | ===Reduction of air on invert reeds=== | ||
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{{youtube> | {{youtube> | ||
- | Didgeridoo, Large strings, | + | ===Selective venting of wind instruments=== |
+ | Long wind instruments such as the bassoon and contrabass clarinet have the ability to play subharmonics using an unusual phenomena of selectively venting small air holes at key locations along their standing waves. this is most commonly done on the bassoon and contrabassoon by venting the low Bb (all keys closed) and allowing a small amount of air to escape the hole for the mid-range A, which results in an A one octave below the one being vented (the A just below low Bb). With an exceptionally skilled player this technique can be used to vent several pitches in the mid range allowing for a low A down to Eb to be played. this technique is easier to produce on reeds that easily speak low notes and pairs well with a very loose embouchure. On the contrabassoon up to three notes of the undertone sequence on the vented A have been documented. A similar technique can also be done on the contrabass clarinet. In both cases the sound of the generated notes is rough and the technique is exceptionally fickle and difficult to produce, and does not represent an easily repeatable, reliable, or fast technique for compositional purposes. This kind of selective venting may be possible on other instruments as well and under well constructed circumstances may be able to play many notes of the undertone sequence. | ||
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+ | ===Extension of length=== | ||
+ | Just as the overtone series can be generated from equal divisions of a length-- for example dividing a strings | ||
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+ | ===Notes=== | ||
+ | All of these techniques are only producible on large instruments. The highest starting pitch that is capable of generating this series is on the Terpodion, which is under high resistance with fast spinning, representing a degree of force difficult to make on most instruments that are directly played by a player. The undertone sequence has great potential to allow for instruments to play far lower pitches than are commonly available for a given length of instrument. I wonder if there is a relationship to stopped pipes and the undertone series (a cylinder like a clarinet is 1 octave lower than a conical instrument of the same length) and this may represent the first harmonic of the series. It is also ambiguous how the octave above a fundamental relates to the octave below it and now those relate to both the undertone and overtone series (when moving from the undertone series to the harmonic series is is there a total of 4 octaves or 3 octaves in a row when shifting from one series to another... or perhaps its 2, with the fundamental of each series being the first harmonic of the other). \\ | ||
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+ | [[Harry Partch]] described it as 4 octaves in total in his theory of Otonality and Utonality \\ | ||
+ | {{https:// |