Editing Overtone (section)

== Etymology ==
In [[Hermann von Helmholtz]]'s classic "On The Sensations Of Tone" he used the German "Obertöne" which was a contraction of "Oberpartialtöne", or in English: "upper partial tones". According to Alexander Ellis (in pages 24–25 of his English translation of Helmholtz), the similarity of German "ober" to English "over" caused a Prof. Tyndall to mistranslate Helmholtz' term, thus creating "overtone".<ref name="etymology"/> Ellis disparages the term "overtone" for its awkward implications. Because "overtone" makes the upper partials seem like such a distinct phenomena, it leads to the mathematical problem where the first overtone is the second partial. Also, unlike discussion of "partials", the word "overtone" has connotations that have led people to wonder about the presence of "[[Subharmonic|undertones]]" (a term sometimes confused with "[[Combination tone|difference tones]]" but also used in speculation about a hypothetical "[[undertone series]]").

==="Overtones" in choral music===
In [[barbershop music]], a style of four-part singing, the word ''overtone'' is often used in a related but particular manner. It refers to a [[psychoacoustic]] effect in which a listener hears an audible pitch that is higher than, and different from, the fundamentals of the four pitches being sung by the quartet. The barbershop singer's "overtone" is created by the interactions of the upper partial tones in each singer's note (and by sum and difference frequencies created by nonlinear interactions within the ear). Similar effects can be found in other ''a cappella'' polyphonic music such as the music of the [[Georgia (country)|Republic of Georgia]] and the [[Music of Sardinia|Sardinian]] ''[[cantu a tenore]]''. Overtones are naturally highlighted when singing in a particularly resonant space, such as a church; one theory of the development of [[polyphony]] in Europe holds that singers of [[Gregorian chant]], originally monophonic, began to hear the overtones of their monophonic song and to imitate these pitches - with the fifth, octave, and major third being the loudest vocal overtones, it is one explanation of the development of the [[triad (music)|triad]] and the idea of [[consonance]] in music.

The first step in composing choral music with overtone singing is to discover what the singers can be expected to do successfully without extensive practice. The second step is to find a musical context in which those techniques could be effective, not mere special effects. It was initially hypothesized that beginners would be able to:<ref name=hnm>{{cite journal |last1=Hinds |first1=Stuart |title=New Music for chorus with Overtone Singing |journal=The Choral Journal|publisher=[[American Choral Directors Association]]|date=April 2007 |volume= 47| issue = 10 |pages=20–31|jstor=23557310}}</ref>

*[[glissando]] through the partials of a given fundamental, ascending or descending, fast, or slow
*use vowels/text for relative pitch gestures on indeterminate partials specifying the given shape without specifying particular partials
*improvise on partials of the given fundamental, [[Ad libitum|''ad lib.'']], freely, or in giving style or manner
*find and sustain a particular partial (requires interval recognition)
*by extension, move to an adjacent partial, above or below, and alternate between the two

Singers should not be asked to change the fundamental pitch while overtone singing and changing partials should always be to an adjacent partial. When a particular partial is to be specified, time should be allowed (a beat or so) for the singers to get the harmonics to "speak" and find the correct one.<ref name=hnm/>

===String instruments===
{{Main|String harmonic}}
[[File:Flageolette.svg|thumb|upright=1.5|Playing a harmonic on a string. Here, "+7" indicates that the string is held down at the position for raising the pitch by 7 half notes, that is, at the seventh fret for a fretted instrument.]]
String instruments can also produce multiphonic tones when strings are divided in two pieces or the sound is somehow distorted. The [[sitar]] has sympathetic strings which help to bring out the overtones while one is playing. The overtones are also highly important in the [[tanpura]], the drone instrument in traditional [[Music of India|North and South Indian music]], in which loose strings tuned at octaves and fifths are plucked and designed to buzz to create sympathetic resonance and highlight the cascading sound of the overtones.

Western string instruments, such as the [[violin]], may be played close to the bridge (a technique called "[[sul ponticello]]<ref>{{Cite book|last=Allen|first=Strange|title=The Contemporary Violin: Extended Performance Techniques|url=https://www.amazon.com/Contemporary-Violin-Performance-Techniques-Instrumentation-ebook/dp/B009D1FRF0|access-date=2021-02-27|via=www.amazon.com|date=21 January 2003 |publisher=Scarecrow Press }}</ref>" or "am Steg") which causes the note to split into overtones while attaining a distinctive glassy, metallic sound. Various techniques of [[Bowed string instrument extended technique|bow pressure]] may also be used to bring out the overtones, as well as using string nodes to produce natural harmonics. On violin family instruments, overtones can be played with the bow or by plucking. Scores and parts for Western violin family instruments indicate where the performer is to play harmonics. The most well-known technique on a guitar is playing [[flageolet tone]]s or using [[distortion]] effects. The ancient Chinese instrument the [[guqin]] contains a scale based on the knotted positions of overtones. The Vietnamese [[đàn bầu]] functions on flageolet tones. Other multiphonic [[extended techniques]] used are [[prepared piano]], [[prepared guitar]] and [[3rd bridge]].

===Wind instruments===
Wind instruments manipulate the overtone series significantly in the normal production of sound, but various playing techniques may be used to produce [[multiphonics]] which bring out the overtones of the instrument. On many woodwind instruments, alternate fingerings are used. "Overblowing<ref>{{Cite web|title=Flute|url=http://hyperphysics.phy-astr.gsu.edu/hbase/Music/flute4.html|access-date=2021-02-27|website=hyperphysics.phy-astr.gsu.edu}}</ref>", or adding intensely exaggerated air pressure, can also cause notes to split into their overtones. In brass instruments, multiphonics may be produced by singing into the instrument while playing a note at the same time, causing the two pitches to interact - if the sung pitch is at specific harmonic intervals with the played pitch, the two sounds will blend and produce additional notes by the phenomenon of [[sum and difference tones]].

Non-western wind instruments also exploit overtones in playing, and some may highlight the overtone sound exceptionally. Instruments like the [[didgeridoo]] are highly dependent on the interaction and manipulation of overtones achieved by the performer changing their mouth shape while playing, or singing and playing simultaneously. Likewise, when playing a [[harmonica]] or [[pitch pipe]], one may alter the shape of their mouth to amplify specific overtones. Though not a wind instrument, a similar technique is used for playing the [[jaw harp]]: the performer amplifies the instrument's overtones by changing the shape, and therefore the [[acoustic resonance|resonance]], of their [[vocal tract]].

===Brass Instruments===

Brass instruments originally had no valves, and could only play the notes in the natural overtone, or harmonic series.<ref name=sj1>{{cite book |last1=Schmidt-Jones |first1=Catherine |title=Sound, Physics, and Music |date=2015 |publisher=CreateSpace Independent Publishing Platform}}</ref>

Brass instruments still rely heavily on the overtone series to produce notes: the [[tuba]] typically has 3-4 valves, the tenor [[trombone]] has 7 slide positions, the [[trumpet]] has 3 valves, and the [[French horn]] typically has 4 valves. Each instrument can play (within their respective ranges) the notes of the overtone series in different keys with each fingering combination (open, 1, 2, 12, 123, etc). The role of each valve or rotor (excluding trombone) is as follows: 1st valve lowers major 2nd, 2nd valve lowers minor 2nd, 3rd valve-lowers minor 3rd, 4th valve-lowers perfect 4th (found on piccolo trumpet, certain euphoniums, and many tubas).<ref name=BTP>{{cite journal |title=Brass Techniques and Pedagogy |url=https://pressbooks.palni.org/brasstechniquesandpedagogy/chapter/brass-acoustics/ |website=PalniPress|date=24 August 2020 |last1=Weidner |first1=Brian }}</ref> The French horn has a trigger key that opens other tubing and is pitched a perfect fourth higher; this allows for greater ease between different registers of the instrument.<ref name=BTP/> Valves allow brass instruments to play chromatic notes, as well as notes within the overtone series (open valve = C overtone series, 2nd valve = B overtone series on the C Trumpet) by changing air speed and lip vibrations.

The [[tuba]], [[trombone]], and [[trumpet]] play notes within the first few octaves of the overtone series, where the partials are farther apart. The [[French horn]] sounds notes in a higher octave of the overtone series, so the partials are closer together and make it more difficult to play the correct pitches and partials.<ref name=sj1/>

===Overtone singing===
[[Overtone singing]] is a traditional form of singing in many parts of the [[Himalayas]] and [[Altay Mountains|Altay]]; Tibetans, Mongols and Tuvans are known for their overtone singing. In these contexts it is often referred to as [[Overtone singing|throat singing]] or [[Tuvan throat singing|khoomei]], though it should not be confused with [[Inuit throat singing]], which is produced by different means. There is also the possibility to create the overtone out of fundamental tones without any stress on the throat.

Also, the overtone is very important in singing to take care of vocal tract shaping, to improve color, resonance, and text declamation. During practice overtone singing, it helps the singer to remove unnecessary pressure on the muscle, especially around the throat. So if one can "find" a single overtone, then one will know where the sensation needs to be in order to bring out vocal resonance in general, helping to find the resonance in one's own voice on any vowel and in any register.<ref>{{cite journal|last=Hinds |first=Stuart |title=Argument for the Investigation and Use of Overtone Singing |id={{ProQuest|1402609}}|journal=Journal of Singing |date=September 2005}}</ref>