The Warble is a natural vibrato effect occurring in some flutes when the fundamental (all holes covered) is played. Some folks find this to be a pleasing attribute and others do not.
While many folks have read of this effect not too many people have actually had the opportunity to listen to it with even fewer having NAF flutes that will actually exhibit this effect.
Within the Authors personal collection this effect is observed in only approximately 10% of the flutes.
Betty Austin Hensley in her book covering the early 20th Century Flutist Thurlow Lieurance and his Flute Collection referred to this effect as a bubble and indicates that only approximately 10% of his flutes would produce a good bubble. (Hensley, 1990)
Educator Edward Wapp Wahpeconiah (Comanche/Sac and Fox) wrote that:
There were three main characteristics of the flute that were preferred by both makers and players and are yet important to players. The two most important were a pleasing tone and a usable arrangement of scale tones; otherwise, the flute was discarded and never played. The third characteristic, which is not found on many flutes, was a warbling sound on the lower pitch of the scale. The warble, in actuality, is a rapid alternation between two different pitches (acoustical beats) and was probably incorporated into the instruments design to imitate vocal pulsation that is characteristic of Indian Singing. This sound was and is yet preferred by flute players and achieved by only a few makers. (Wapp, 1984)
Later Ed Wapp wrote the following to me in a personal letter:
One thing helps to explain another. The flute used the vocal love song as source material. In singing the vocal love song, the singer tried to disguise the voice. As well, an aspect of vocal performance practice of the love song, a vocal pulsation was sung on the fundamental. The warble imitates the vocal ornamentation. My Grandfathers flute as the warble. Doc Tate Nevaquayah really liked the flute. I remember Doc Payne when he was trying to figure out the warble. Several makers around Anadarko claimed that they knew how to put it in a flute. Basically, and it takes precision to do it, the Nick on the lip [splitting edge] causes [it]
.. I had to laugh. The flutes that we use at IAIA [Institute of American Indian Arts, Santa Fe, NM] have the warble, and they are made from PVC pipe. One of the female students got one with a strong warble. When she played it, it frightened her. (Crawford, 7/01)
On the tape that accompanies the Thesis Instrumental and Vocal Love Songs of the North American Indians there are three recordings exhibiting this effect: Meskwaki Melody, Wilson Rolberts, 1956; Winnebago Melody 1964 and a Kiowa Melody, Everett Cozad, 1964. (Riemer, 1978)
On the tape that accompanies the Thesis The Flute of the Canadian Amerindian there are 8 recordings exhibiting this effect: Kiowa Flute Song, Belo Cozad, 1954; Meskawaki, Love Song for the Flute, Wilson Roberts, 1956; Winnebago, Love Song, 1964; Comanche, I Saw and Eagle Fly, Doc Tate Nevaquaya, 1964; Potawatomi, First Love Song for Flute, Ed Wapp, 1982; Potawatomi, Second Love Song for Flute, Ed Wapp, 1982; Comanche, I Saw and Eagle Fly, Ed Wapp, 1982; Comanche, Modern Courting Song, Ed Wapp, 1982. Two of these appear to be the same as two of those on the Riemer tape. (Conlon, 1983)
So far, as nearly as I can determine, the particular effect has been commented upon the most by Doc Payne (Richard W. Payne).
In 1988 Doc wrote:
Using a properly constructed Plains flute with all tone holes covered, diaphragmatic air will produce the tonic F sharp in warm vibrato. This accentuated vibrato, known as the warble, is an important feature of traditional Plains Indian flute playing. It is accentuated by directing the air blade slightly high over the fipple edge and further enhanced by added support of the air column slightly compressed in the pressure chamber of the flute. Tone frequency of the vibrato can be increased by as much as a half step by pushing cold air to produce a multiphonic warble, the tempo and tonality of which can be controlled in an effective manner. This warble, scrupulously avoided by organ pipe builders who term it burble, is a prized attribute of the Plains flute, which can be driven with considerable variation in air pressure, in contrast to the organ pipe. (Payne, 1988)
Then in 1999 Doc wrote:
The Toubat flute (this is the name that Doc gave a specific flute of his own design) requires particular skills in playing technique. In the old style of Plains flute playing, the vigorous multiphonic warble on the fundamental note was highly regarded. This requires careful alignment of the block, nest and roost so that the air stream is directed slightly high on the fipple edge [sic; splitting edge]. Breath control is critical to execution of the oscillating warble; this is accomplished with warm diaphragmatic breathing dynamics. Air compressibility is also aided by providing slight impediment to the air stream, resulting from a slightly narrowed embouchure hole and air vent. (Payne, 1999)
From trial and error observations it appears to me that the effect is generally best observed with the bird/block s leading edge being just forward of the chamber separating block. In addition to the position of the block an increase in air pressure (creating a higher compression of the air in the air chamber) appears to be a general requirement for the production of this natural vibrato (i.e. blow a bit harder).
Excluding double bore NAFs I have five principal flutes that I use to demonstrate the Warble. A D# flute by Ken Light; an E flute by James Gilland; an F# flute by Doc Payne (a, k, a, the Toubat flute), a G by Timothy Nevaquaya, and a G Flute by Doc Oliver Jones. Each flute seems to have an observable difference in the velocity of the oscillation of the vibrato. Ken Lights is by far the fastest while Timothy Nevaquayas is the slowest. Doc Jones flute, appears to be in the middle and has one of the more stable and consistent warbles.
The Ken Light flute and the Doc Payne flute have a metal nest. The Doc Jones flute has a wood nest. The James Gilland flute has the air channel cut into the body of the flute while the Timothy Nevaquaya flute has the air channel cut into the bird/block
Doc Payne was of the tentative opinion that a narrow mouthpiece end might possibly be a perquisite, however, the James Gilliand flute, being constructed of river cane, has a totally open air chamber and, interestingly enough, appears to me to be one of the easiest to demonstrate this effect with. The point that Doc Payne was most concerned about making was that an increase in compression within the air chamber is required (whether by the player blowing harder or possibly simply by wind way design).
In preparation for a presentation on this topic at the first INAFA convention (2001), I took my dial micrometer and set about to measure every possible and conceivable attribute that I could possibly identity that would definitely differentiate what physical characteristics are required to be present for this effect to occur. After taking a variety of measurements on four of the flutes that Warble and flutes that do not I was not able to arrive at any single characteristic or combination of characteristics that could be identified as being physically responsible for this effect, that would at least be apparent by physical measurement (see 3rd paragraph from end).
Of these five flutes, as far as I know, Doc Payne and Dr. Oliver W. Jones, Jr., are the only builders that specifically set out to create flutes that will exhibit a natural Warble, with the possible exception of Timothy Nevaquayah. In a conversation with me on this topic, in April of 2001, Doc Payne confessed that not all the flutes that he builds exhibit this effect; those that do not he destroys. While on this subject, Doc Payne is not really in the business of building flutes to sell. He only builds a few each year. (Crawford, 4/01).
Doc Jones, Wild Horse Mountain Flutes, La Jolla, CA, also builds warbling flutes for sale. In a conversation with me on 2/7/02 Doc Jones stated that he has yet do discover with certainty what physical characteristics or attributes are in whole required to produce a warble; however, he has discovered, never the less, that for his flutes there are two very specific criteria necessary in their construction for them to have the warble characteristic. 1) The air column spacing under the block has to be very thin, 1/64 of an inch (.0156) and 2) The distance from the block [bird, saddle] across to the beveled splitting edge must be 10/32 of an inch (.3125). (Crawford, 2/02)
Flute Builder, Michael Searching Bear Smallridge, Searching Bear Flutes, Ravenna, OH, stated that he is now achieving consistency with building warbling flutes:
Every flute I make now I am able to find where it will warble without even blowing on it. So at least with my flutes and the way I make them, its all in where the totem is positioned in relation to the bottom of the window. I tend to burn my windows at a slight slanted angle. I have also found that just because it warbles does not mean this is the best position (the totem) for the rest of the notes on the flute. (Crawford, 4/02).
I can comment and agree with Michael on positioning in that my Doc Payne flutes (which I am quite pleased with, and keep in perspective that each one is unique) best block/bird/saddle position for a solid warble is not the best position for most of the rest of the notes on the flute.
Additionally, Michael Searching Bear Smallridge, further commented after reading an advance copy of this Appendix:
Thanks for the warble info. With all this information and my experiences with my flutes, I can come to one conclusion. Nobody knows why it happens or how it happens. More so on the latter. Lew Paxton has exact dimensions that causes it, as Lew would, but I find them to be incorrect for mine. Maybe it's a weather thing. Atmospheric pressures? Also, as far as the drones go, I tend to make my drones slightly off key from each tube. You stated 30 cents. I go about 10 cents. This would get me the cyclic phase. But,,,,,,, I created an F# of African Mahogany, if wood matters, and both tubes are precisely tuned exactly the same. I would assume it would phase cancel each other out but it warbles better than any of my other drones. You don't even need to try to create the warble. It just does it!
All my drones, however, seem to warble. Knowing quite a bit, or apparently just enough, about music, I made my first drone knowing and understanding the phase cancellation effect. Being in the studio recording all these years I actually picked up something!
This F# I spoke of seems to shoot down the phase cancellation theory. On the single tubed flutes, I have noticed that a sharp cutting edge pretty much destroys the possibility of warble. Many flute makers go for this sharp edge. But I find, at least in my flutes, the very opposite. I have actually made flutes that will not jump when you over blow! I like that. Some folks don't. They feel they are getting robbed of the extra note. All I tell them is to take all their fingers off the flute; there is your octave note. (At least in the 5 hole version). I have played many a flute that was just too hard to keep from jumping. I hate when that happens. Especially when you are not ready for it! I also must add, and I believe you were quoting me, that I have had several flutes that warbled in the construction phase only to lose it after dipping the flute. Figure that one out???
All I know is that in my flutes the angle of the window (attention to the back side of the window on the bottom - not the cutting edge) and the placement of the totem is the most critical requirements for the warble. The edge of the totem (be it the inside of the chimney or no chimney) must line up with the bottom of the angle inside the flute. So the totem may cover a slight bit of the hole on the nest. As well as the blunt cutting edge.
I'm not sure about the Nick in the cutting edge though. Mine, as far as I know, are not nicked. I would think this would cause a bit of a rasp sound. In closing, all I can say is most of the flutes I create (70%) warble during construction phase and I really am not trying to create it. I do know where to place the totem in relation to the window to get mine to warble. That is if it is going to warble I know once I try to get the warble, I won't be able to............... Wa do (Crawford, 4/02)
In a phone conversation with Lew Price, Lew states that while he personally is not attracted to this effect, it is a result of a flutes tendency to over blow. To increase the tendency of a NAF to over blow, given equal diameters, a change in the ratio of the length of the air chamber to the sound chamber can contribute to this tendency. This is best accomplished by lengthening the air chamber. In addition to an increase in the length of the air chamber the next important variable is the angle of the bird/block chimney and the shape of that chimney, i.e. the length of the sides; the bird/block variables are open to experimentation with the important objective being that of reducing the induction of outside air into the air stream as it crosses over to the lip or edge. (Crawford, 5/01).
One flute builder emailed me that he had crafted a flute that warbled very, very loudly and the speed of the warble was quite slow. After I dipped the flute for the finish, the warble was gone! [see Michael Smallridge Comment above]
R. Carlos Nakai sent the following to me in response to an inquiry on this topic:
In actuality, the warble sound which is sounded at the all closed position only on all five and six holed flutes is, to my experience, merely an indicator that the sound producing mechanism is well made and is correctly positioned for optimum air flow from the air chamber over the block and directed by the saddle/bird mechanism against the distal edge of the body tube hole. The oscillations of air movement coincidence with the Coriolis effect and the standing sine wave in the body tube helps to make this effect possible. Thats all, no mystery as my 1985 air pressure smoke tests have shown!
As an effect, if one only played the flutes tonic pitch then the warble effect would be a useful embellishment for modulating that singular pitch. The variations of air intensity in effecting a more or less pronounced and sometime faster or slower warble is also an indicator of effective use of embouchural air control by the flutist and adds to the quality of the resolving pitch.
In more cases than not, the subsequent quavers/vibratos that are performed at various stages of ones performance are matched to the warble so upon returning to the resolving pitch, if it is the lowest one, will be the use of the warble rather than the vibrator. Simple but difficult in practice! (Crawford, 4/02)
I have two drone flutes and both of these flutes exhibit a warble. Only one of these flutes is constructed in such a manner that I can blow down either bore, individually, as well as both together. Neither bore, individually, will produce a warble yet a warble is created when playing both bores, as a drone, in the fundamental. I have talked to a few other owners of double flutes who also have commented that their drone flute also warbles.
The drone warble then appears to be the result of an oscillation between the tones produced in each bore created by the fact that each bore is not quite precisely tuned to the other. My tuner did show a difference of about 30 cents (100 cents for a full 1/2 step to the next note) between each bore of this one A drone NAF.
What is clearly happening with the drone warble is termed a beat frequency: which results from the interference between two sound waves of slightly different frequencies. The frequency of the beats will be equal to the difference between the frequencies of the sound waves. Since the beats will disappear if the two frequencies are made identical [Conversely, it is unlikely that the beat frequency can be perceived once its velocity gets above 30/second], the phenomenon is useful in the tuning of musical instruments. Beats can occur between the fundamental of one pitch and a higher harmonic of another as well as between the two fundamentals [a tuning technique used by some players of stringed instruments]. (Randel). Ed Wapp, in an earlier paragraph, also offered a similar explanation.
This same explanation may also hold true for all mono flutes, and helps to explain the differences in the warble speed described in different flutes in an earlier paragraph; the differences simply being differences in the frequencies of the secondary tone being produced.
However, an understanding of the beat frequency concept being a physical explanation for the warble still leaves the mystery of how this effect can be induced by construction into the Native American Flute.
The drone effect has led me to believe that something must be happening at the splitting edge (distal edge of the sound chamber hole) to create, in effect, a balance of some type between the fundamental note and an overblown note (whether another fundamental note of a different pitch or simply some higher harmonic) and or possibly even a co-existence of two air streams. Whether this is due to a part of the air stream being delayed (thousands of a second), which could occur by the splitting edge being angled) or possibly compressed, or the angled windows used by Michael Smallridge or caused by the splitting edge possibly being nicked (or angled) somewhat, or for that matter some other as yet undiscovered explanation, is unknown to me. It is to be hopped that some future researcher will be able to resolve this issue with clarity (and quite possibly R.Carloss explanation already accomplishes this).
I can comment, that two of my warbling flutes have noticeable nicks at the splitting edge, when viewed with magnification; both Timothy Nevaquayas and Doc Oliver Jones flutes have this characteristic (Doc Jones flute also shows the splitting edge to be slightly angled across the opening). While I do not know if this is the sole reason for these flutes to Warble, it does cause me to speculate that there might possibly be several different and correct explanations as to how to induce a warble into a flute.
As to how one sets out to specifically create this effect I can only point you in the direction of Doc Jones, Doc Paynes Lew Prices, Michael Smallridges and Ed Wapps observations as well as my own regarding the drone effect.
A closing comment of curious interest: French craftsman during the 19th Century (1800s), when building organ flue pipes found it to be important to have certain pipes (referred to as Celeste) constructed in two ranks with one turned slightly sharp to create what was referred to as an undulating sound (a.k.a. beat frequency and Warble). (Randel, 1996)
Footnote 1: The author, Tim R Crawford, considers this topic to still be a work in progress and welcomes any additional information that anyone would like to share ( )
Footnote 2: Portions of this text were originally used in a presentation on this topic at the first INAFA (International Native American Flute Association) held at Kent State in June of 2001. During the closing ceremony of the convention names were drawn of those that had entered a fund raising raffle for INAFA; as fortune would have it my name was drawn for the Doctor Oliver Jones Warbling flute that is described herein.
Footnote 3: This is an unabridged copy of an abridged version which appears in my book, Flute Magic: An Introduction to the Native American Flute, 3rd edition, Rain Dance Publications, 2003.
Conlon, Paula. 1983, The Flute of the Canadian Amerindian. Masters Degree Thesis-Carleton University.
Crawford, Tim R. 1999, Personal correspondence from Lew Paxton Price, 10/26/99
-------Phone conversation with Dr. Richard W. Payne, April 12, 2001
-------Phone conversation with Lew Paxton Price, May 6, 2001
-------Personal correspondence from Edward Wapp, 7/01/01
-------Phone conversation Dr. Oliver W. Jones, February 7, 2002
-------Email from R. Carlos Nakai, 4/2/02
-------Email from Michael Smallridge, 4/3/02 & 4/5/02
Hensley, Betty Austin, 1990 Thurlow lieurance Indian Flutes. Kansas: nap.
Payne, Richard W., 1988 The Plains Flute, The Flutist Quarterly, Volume 13(4)
------- 1999, The Native American Plains Flute. Oklahoma: Toubat Trails Publishing Company
Randel, Don Michael, 1996. The New Harvard Dictionary of Music [8th edition]. Massachusetts: The Belknap Press of Harvard University
Riemer, Mary F., 1978. Instrumental and Vocal Love Songs of the North American Indians. Master Thesis-Wesleyan University.
Wapp, Edward R., 1984 The American Indian Courting Flute: Revitalization and Change. Sharing a Heritage: American Indian Arts. Contemporary American Indian issues Series No. 5, Los Angeles: UCLA, UCLA Publications Services Department.