In some ways, the contemporary Native American flute doesn’t sound like the indigenous flutes of the far past. Recently, flutes have been refined through modern preferences. First they have been tuned to the piano and particular scales. Much of their timbre has been cleaned of the buzzy, raspy, and breathiness. And they have lost their ability to warble, which is a sound that appears to have been highly prized in earlier times. Such flutes could be blown forcefully with all holes covered while the pitch of the flute would repeatedly jump an octave and then immediately fall an octave. When first heard, many mistake the warble for a strong vibrato or a flutter tongue.
A number of recordings with the warble can be found on the web, such as the Belo Cozad recording found on http://www.spottedeagle.com/toubat.htm by clicking the "Late 1920's recording of the flute". [The 1920s date may be inaccurate, another similar recording was dated 1941.] Belo Cozad was an old Kiowa flute player (1864-1950) who saw great changes during his life.
At Wild Horse Mountain Flutes there is some background music, which is a recording of Turkey Legs, a Cheyenne flute player. Also the American Philosophic society has a recording of Jaspar Blowsnake, a Winnebago flute player. This recording (1937?) is found about half way down the following web page: http://www.amphilsoc.org/library/digcoll/sounds
Today, the warble is not a popular sound. The warble seems to be an acquired taste for a few, and a major dividing line between some traditionalist and the modernist. I believe a lot of the current popularity of contemporary NAF has a lot to do with a few musicians during the 80s and early 90s created a sound that was appealing to the masses. But it was different over 100 years ago.
One of the earliest mentions of the warble came from Alfred Longley Riggs in 1869. He provided a detailed description of the flutes construction, musical tuning, and the warble which was called the ‘bubbling’.
The pipe or flute is called cho-tan-ka, which means literally, "big-pith." It has two varieties, one made of wood, and the other of bone. The first is the most common, and much resembles the flageolet. It is made by taking the sumac—a wood which has the requisite "big-pith"—a straight piece nineteen or twenty inches long, and, when barked and smoothed down, an inch and a quarter in diameter. This is split open in the middle, and the pith and inner wood carefully hollowed out to make a bore of five eighths of an inch diameter, extending through the whole length, except that it grows smaller at the mouth-piece, and at a point four inches below that, it is interrupted entirely by a partition three eighths of an inch thick, which is left to form the whistle. The halves are glued together. Finger-holes one quarter of an inch in diameter, and usually six in number, are burnt along the upper face. On the same face the whistle is made by cutting a hole three eights of an inch square each side of the partition. Then, over these, and connecting them, is laid a thin plate of lead, with a slit cut in it, a little more than an inch long and three eights of an inch wide. On top of this is a block of wood, two inches long and three fourths of an inch wide, flat on the bottom, and carved above into rough likeness of a horse; and a deer-skin string binds the whole down tight. A brass thimble for a mouth-piece, some ribbon streamers, a few lines of carving, and a little red and yellow paint, and the instrument is complete.
The pitch of the particular pipe to which this description mainly refers, seems to have been originally A prime, and changed to G prime by boring a seventh hole. One formerly in my possession was pitched at E flat prime; and from it the airs which are here give were taken down.
The second variety of the cho-tan-ka is made of
the long bone of the wing or thigh of the swan and crane. To distinguish the first from the
second, they call the first the murmuring (literally 'bubbling') cho-tan-ka, from the
tremulous note it gives when blown with all the holes stopped.
(pg. 476, “TAH’-KOO WAH-KAN; The gospel among the Dakotas”, by Stephen R. Riggs, with an appendix “Dakota songs and music”, by Alfred Longley Riggs )
It is typical for such flutes to only warble when all finger holes are covered. Also players are all too aware that little adjustments are also required before playing. If the spacer under the block is not glued down, this spacer will need to be positioned properly before the warble can be initiated. Then the block can then be adjusted to control the rate of the warble. This is apparent in description of the Omaha flute:
The flute or flageolet, nicude tu"ga (tu"ga,
'big'), was generally made of cedar; it was 20 inches in length and an inch in diameter. The
holes---six in number---began about 4 inches from the lower end and about an inch apart. The
stop was placed 5 or 5 1/2 inches from the mouthpiece at the end. This instrument had a flute
like tone but, being made by the 'rule of thumb,' lacked accuracy of pitch. To be acceptable,
a flute must give forth a full, vibrating tone when blown with all six holes closed. It was
interesting to watch men, old and young, take up a flute to test it; they would readjust the
stop piece, bound to the top over the opening and usually carved, and if after several trials
the instrument could not be made to give this vibratory tone the flute would be laid aside and
no words would avail to make the man take it up and play a tune on it. The compass of the
nicude tu"ga was an octave. The intervals did not correspond exactly to our diatonic
(pg. 371, “27th Annual Report of the Bureau of American Ethnology”, by Alice C. Fletcher and Francis La Flesche [1905-1906])
I've been told that the "warble" was like the ground we standing. The melody will start high, fly around a bit but ultimately return to the ground, the "warble". I've noticed new flute players today tend to start at the low note and ascend to the higher notes, which is opposite to this style. Dr. Richard Payne, noted flute historian, said they would just warble, warble, and warble to warm up the flute before they began playing.
Nearly a hundred years before some of these recordings, George Catlin made several trips to paint the Plains Indians and their way of life. In one of his letters, recorded at the mouth of the Teton River in upper Missouri, he writes:
There is yet another wind instrument which I
have added to my Collection and from its appearance would seem to have been borrowed, in part,
from the civilized world. This is what is often on the frontier called a "deer-skin flute," a
Winnebago courting flute, "tsal-eet-quash-to"; it is perforated with holes for the fingers,
sometimes for six, at others for four, and in some instances for three only, having only so
many notes with their octaves. These notes are very irregularly graduated, showing clearly
that they have very little-taste or ear for melody. These instruments are blown in the end, and
the sound produced much on the principle of a whistle. In the vicinity of the Upper
Mississippi, I often and familiarly heard this instrument, called the Winnebago courting
flute; and was credibly informed by traders and others in those regions, that the young men of
that tribe meet with signal success, oftentimes, in wooing their sweethearts with its simple
notes, which they blow for hours together, and from day to day, from the bank of some stream
-- some favorite rock or log on which they are seated, near to the wigwam which contains the
object of their tender passion; until her soul is touched, and she responds by some welcome
signal, that she is ready to repay the young Orpheus for his pains, with the gift of her hand
and her heart. How true these representations may have been made, I cannot say, but there
certainly must have been some ground for the present cognomen by which it is known in that
(pg. 243, Letter #30, “Letters and Notes on the Manners, Customs, and Condition of the North American Indians”, by George Catlin )
The Smithsonian is now touring around the nation an exhibiting called "George Catlin and his Indian gallery". During the DC show, the exhibit included a flute which is cataloged Pawnee Flageolet, about 1830s, wood, hide, lead, sinew, pigment, approx. 21 3/8 x 2 1/2 in. This is one of earliest dated example of the Plain flute. It is interesting that this flute is credited to the Pawnee because some 90 years later, Densmore research the music of the Pawnee and found they did not play the flute. Some of their love songs were preceded by the syllables ee-ee on a low tone in imitation of a flute. I assume Densmore was referring to the warble. Also the informant said, "The flute was courting medicine of a bad kind." I guess the enforced acculturation and culturecide was already taken its toll on the Pawnee culture by the time of Densmore's research.
In surveying a wide variety of historic flutes, I've noticed features that a majority of the historic flutes shared. First, the birds typically had deep side walls around the tone hole. (Pipe organ makers call them ears.) For anybody that plays outdoors with some wind, the importance of this feature is apparent. Second, the cutting edge of the tone hole was typically (but not always) adjustable at the time of making the flute---a metal spacer or plate allowed easy fine tuning of a critical measurement and then later glued down. Both are features that I would recommend to any flute maker that wants to create flutes that naturally warbled. The one other trick is to make sure the stream of air is pointed just above the cutting edge. On 'O' shaped lead spacers, the cutting edge could be dimpled down or slightly beveled. Not many makers like the sound of flutes with low cutting edge, they are too reedy which is a product of strong even harmonics.
Others have written about the warble. Betty Austin Hensley's book on the flutes of Thurlow Lieurance refers to the warble as bubbling, just Riggs had stated some 100 years before in the Dakotas. Dr. Edward Wapp has a few remarks on the warble, which is found on Kevin Locke's web site: http://www.kevinlocke.com/kevin/moreflute.html.
I was originally exposed to the warble through Dr. Richard Payne and Michael Graham Allen. Both were helpful in showing me how to create flutes that warble. For Dr. Payne, the best flutes always warbled and this was reflected in the flutes that he made. A recipe that I've used making flutes that warble is quite simple:
A low cutting edge relative to the turbulent jet of air increases the even harmonics produced. Sometimes this is just enough to make a flute warble. Having a moveable brass saddle so you can reduce the gap of a large true sound hole, allows for more experimenting with controlling the rate of the warble. Such a brass spacer needs to have a beveled cutting edge, so you get the low cutting edge. The bird with its side walls seems to make it easier to control the warble, i.e., the positions of the other elements seem to become less critical.
The nice thing with this sort of setup is the tinker factor. A number of old flutes have a "lead spacer with the cutting edge bent down", which can be thought as a low cutting edge. This form of voicing the pipe is very similar to the approach of pipe organ makers.
Some flute makers will constrain the size of the blow hole and/or the exit hole from the slow air chamber to create more back pressure. This has the benefit of making it harder to overflow the flute past the point of the warble, which is possible. There can be some technique to maintaining a warble. One must blow hard enough with all holes closed, but not too hard.
It is not to say this is the only way to make a flute that warbles. Some flutes have been found to poorly warble because of an air leak. But the approach described above appears to be the most reliable, repeatable way for me to create the warble.
With this technique in mind, if you go back and look at the photos of the historic flutes, you will notice how many have birds with ears and some movable cutting edge (at the time of construction). Makes you think 'Hmmm....' But it could be just a reliable method for voicing a flute. Modern techniques that carve a groove into the flute, is actually very unforgiving if you make a mistake. But just looking at that 1832 flute in the Catlin collection, I'd bet it would warble.
Well, I hope this answers more questions than it creates.