Bob Grealish Method for Tuning Native American Flutes

Bob Grealish

This page describes a detailed method for tuning Native American flutes in the pentatonic minor scale. It is assumed that the flute has a cylindrical sound chamber bore, as opposed to a bore that is tapered or has pertubations.

This tuning method is designed to bring both the notes in the primary scale of the instrument as well as the cross-fingered notes into tune at the same time. While this may seem ambitious for flute makers who are crafting their first flutes, the process is not difficult and will reap long-term benefits.

If you are new to flute crafting, you may wish to start out with a somewhat less ambitious tuning strategy. These are simplified version of this Bob Grealish method and provide the experience and groundwork needed to attempt the more advanced methods:

• Basic-Five Method for Tuning Five-Hole Native American Flutes
• Basic-Six Method for Tuning Six-Hole Native American Flutes

This page of Flutopedia was contributed by Robert Grealish and edited by Clint Goss. It is based on a documented originally posted on the Native Flute Woodworking Yahoo newsgroup on July 23, 2007 and updated on August 5, 2014, as well as addition information provided by Bob in a personal communication on August 12, 2014.

(And no, despite the photo on the upper left, Bob does not use bonsai wood to craft flutes.)

What is cross-fingering?

Start by considering a five-hole Native American flute tuned to the pentatonic minor scale. The primary scale is played by opening one hole at a time up from the foot end of the flute while leaving all the holes below it open:

This gives you the five notes plus the octave note that make up the pentatonic minor scale. On this page, we call these the primary notes and primary fingerings.

However, Native American flutes are capable of playing the notes in between the primary notes. In order to play these “in-between” notes, we close one or more of the holes below the highest open hole. Here are some examples of cross-fingered notes (shown in red) interspersed with the primary notes:

This is called cross-fingering, and it has the effect of flattening a primary note that follows it by some amount — often one or two semitones. By using cross-fingerings to get these “in-between” notes, players can access a much larger variety of melodies. On some flutes, you can play every semitone (or “half step”) in the range of the flute, getting a full chromatic scale.

The Six-hole Native American Flute

There are two predominant scales that are played on six-hole Native American flutes: the Mode One Pentatonic Minor Scale and the Mode Four Pentatonic Minor Scale. These are usually abbreviated “Mode 1” and “Mode 4”.

Playing a six-hole flute in Mode 1 is similar to playing a five-hole flute using these fingerings:

Notice that the fourth hole from the bottom of the flute is always kept closed. It is almost as if the fourth hole from the bottom was not even there.

Likewise, when playing in Mode 4, the standard fingering is:

In Mode 4, the third hole from the bottom of the flute is always kept closed.

On what is called a “Mode 1/4” (i.e. a flute that plays well in both Mode 1 and Mode 4), you should be able to play both scales close to well-tuned for the notes shown above.

Note: This tuning method does not consider the two notes between and . These can only be played, if at all, using half-holed fingerings such as , , and .

Figures 1 and 2 below show fingering charts for Mode 1 and Mode 4 for a mid-range, six-hole, F# Mode 1/4 Native American flute. Solid circles represent closed finger holes and open circles represent open finger holes. The fingerings in dark red indicate cross-fingered notes and the yellow fingerings are for the half-holed notes (notice the partially-filled holes at the bottom of these finger diagrams).

Figure 1: Mode 1 scale for an F# minor pentatonic Mode 1/4, six-hole Native American style flute. Hole 4 is closed.

Figure 2: Mode 4 scale for an F# minor pentatonic Mode 1/4, six-hole Native American style flute. Hole 3 is closed.

If you need a chart for a key of flute other than the F# minor flute shown here, the Basic Native American Flute Design Tool can be useful. Simply set the Fundamental Note and click Calculate. If you want to add the cross-fingered notes, check the “include cross-fingerings” box.

Terms, Concepts, and Definitions

External and internal elements of a Native American flute

This page uses slightly different terminology than other pages on of Flutopedia — terms that you might find more common among the flute-maker community.

The head end and foot end of the flute are referred to as the North and South ends. This page also refers to moving a finger hole North or South (i.e. toward the North end or South end of the flute).

Numbering the holes on a Native American flute

This page also uses Flute Maker Numbering for the holes — playing hole 1 is the hole nearest the South end of the flute. This is a common convention among flute makers since this is the finger holes that is tuned first.

General Strategy

When tuning a flute, you start by tuning the note with all finger holes closed. After that note is tuned, you generally proceed by opening holes at the South end and proceed up the flute, tuning each finger hole and the holes below it open. This is the “primary” note that you are tuning for each hole.

Each finger hole starts out small, and its note is flatter than the target pitch for that note. You make a note sharper to bring it into tune in three ways:

1. enlarging the hole opening,
2. moving the hole farther North (toward the mouth end), and/or
3. decreasing the thickness of the wall of the flute at that hole.

Since the wall thickness and initial North/South location are largely pre-determined when you begin tuning the flute, the actual tuning process is commonly done by enlarging the finger hole. However, while you are enlarging the hole, you have the opportunity to move the center of it North or South slightly, still keeping it round. If you’re using tapered burning sticks, you do this by burning a crescent off of the North or South rim of the existing hole. Alternatively, you can just enlarge the whole thing by keeping the pressure even on all sides of the existing hole.

Moving a finger hole and making it larger will both have the effect of sharpening the primary note. However, making a finger hole larger will have more of an effect on the cross-fingered notes than making moving the finger hole.

For example, if you want to sharpen a primary note, such as , a little bit and its corresponding cross-fingered note a lot, you could enlarge hole 3 at the South end. This will make it larger while not moving it North. Both notes will get sharper, but the effect on the cross-fingered note will be greater.

Conversely, if you want to sharpen the primary note more than the cross-fingered note, burn or file the North rim of the hole to enlarge it. The hole will move North, and the final hole when it’s in tune will be smaller than if you burn the South end. In this case the primary note will get sharper, but with less sharpening effect on the cross-fingered note.

Hole-by-hole procedure

Let’s assume you are making an F#, pentatonic mode 1/4 flute. The primary notes of the F# mode 1 pentatonic minor scale are F#, A, B, C#, E, F# (see the Figure 1 above). These are the target pitches of the fingering sequence keeping hole 4 closed:

The primary notes of the mode 4 scale are F#, A, B, D, E, F# (see the Figure 2 above). These are the target pitches of the fingering sequence keeping hole 3 closed:

The cross-fingered notes (shown in red in Figures 1 and 2) are between these primary notes. Notice that there are two semitones between some of the primary notes and three semitones between others. For instance, the first cross-fingered note is an A# (), between A () and B (). However, between C# () and E (), there are 3 semitones, and therefore two cross-fingered notes ( and ). Both of these are considered cross-fingered notes, but we are only going to tune one of them. The other one will end up being in tune close enough.

First, tune the fundamental note of the flute () by cutting the foot end back or by placing and enlarging direction or tuning holes. Next, using the Flute Sheet Excel spreadsheet, NAFlutomat, or another method described on the Finger Hole Placement page, calculate where your playing holes will be. Start by designing them all close to the same diameter and then adjust the hole diameters until the finger spacing is reasonably even. Don’t design the holes too big if you want to tune the cross-fingered notes.

Mark the locations of the finger holes on the flute. Hereafter I will assume you are burning the holes, but if I say to burn a hole, you could just as well grind or file the holes instead of burning. Making a finger hole larger by drilling might not allow you to adjust the North-South position of the finger hole, because the drill bit will tend to center itself in the previously drilled hole, and it will enlarge it all around. Therefore, the following method doesn’t apply to drilling. Start with hole 1 and move up. Start each hole small and tune it up before starting on the next hole. Tune it by gradually enlarging it while checking the notes as follows: (NOTE: This is the basic method. See the addendum at the end about refining this method.)

• If the primary note is flatter than the cross-fingered note: enlarge the hole on its North end;
• If the cross-fingered note is flatter than the primary note: enlarge the hole on its South end;
• If both notes are flat by the same amount: enlarge the hole concentrically.

Hole 1:

A:   

This hole is straightforward: Just make it larger gradually until it is in tune with A. After hole 1 is tuned, check the tuning for the fundamental note () to see if it is still in tune.

Hole 2:

A#: 
B:   

Enlarge hole 2 to bring it in tune with a B. Each time you enlarge hole 2 a little bit, check the tuning of the B (), and also check the A# (). B is the primary note being tuned, and A# is the cross-fingered note. Both notes will be flat at first.

Here is an example of how the tuning for hole 2 might proceed. It illustrates how you decide which portions of the hole to make larger:

• Let’s say the B () is 30 cents flat. Before you enlarge it, check the A# (). Let’s say the A# is 20 cents flat. So the primary note (B) is flatter than the cross-fingered note (A#). In this situation, you will want to move hole 2 North more than you want to enlarge it. This will sharpen the B more than the A#. So you would make hole 2 a little bit larger on the North end.
• Now let’s say both the B () and the A# () are 15 cents flat. You would make hole 2 a little bit larger concentrically and then check it again.
• Next, let’s say the B () is 5 cents flat and the A# () is 8 cents flat. This time you would make hole 2 larger just a little on the South end.
• Finally, say that both notes are 3 cents flat. Again, enlarge hole 2 concentrically, just a little, until both notes come into tune.

After hole 2 is tuned, check the tuning for hole 1 () to see if it is still in tune with A.

Hole 3:

C:   
C#: 

Hole 3 is similar to hole 2. Each time you enlarge hole 3 a little, check the primary note (C#: ) and the cross-fingered note (C: ). If the cross-fingered note (C) is flatter than the C#, enlarge hole 3 on the South rim. If the C# is flatter, enlarge hole 3 on the North rim. If C and C# are both flat by the same amount, enlarge the hole concentrically.

After hole 3 is tuned, re-check the tunings for hole 2, hole 1, and the fundametal note (). At this point, you may start to see some “drift” in notes you have tuned earlier. This can happen, because making a finger hole larger increases the volume inside the sound chamber slightly. This affects the tuning of the notes below it. Fortunately, the effect is to make the previously tuned notes slightly flat, so you can simply make the corresponding finger holes slightly larger.

Hole 4:

C#: 
D:   

Hole 4 is a little different. When the flute is played in mode 1 pentatonic minor, this hole is kept closed. If hole 4 is open, then you are playing in mode 4 pentatonic minor (with some exceptions noted below). Therefore, whenever hole 4 is open, hole 3 will likely be closed. When playing in mode 4, the fourth note of the scale is D rather than C#, and it is played (and therefore, tuned) with hole 3 closed. Now this looks like a cross-fingering, but you should think of it differently. Think of it as though hole 3 didn’t exist, and hole 4 and all the holes below it (hole 1 and hole 2) are open. It should play a D this way.

The cross-fingered note for hole 4 is a C#, which is played in mode 4 with holes 2 and 3 closed. Since you might play this flute in mode 4, hole 4 should be tuned with its cross-fingered note in mind also. Therefore, as you are enlarging hole 4, check the primary note D () and the cross-fingered note C# (). Again, if the C# is flatter than the D, enlarge hole 4 on the South end, and vice versa if the D is flatter.

Holes 5 and 6 are tuned with hole 4 closed, as though this was a 5-hole flute. This is because it is more important to tune the pentatonic mode 1 scale because it is used more than mode 4. Actually, the mode 4 scale will end up being in tune also.

Hole 5:

D:   
D#: 
E:   

When tuning hole 5 (E), since it is 3 semitones above hole 3 (C#), there are two cross-fingered notes below it. The D is played with and the D# is played with  . find that I use the D more, that it is more critical to get right, and that if I tune the D correctly, the D# will also be in tune anyway. So when I am enlarging hole 5, I check the primary note, E () and the cross-fingered D (). As above, if the cross-fingered note is flatter than the primary note, enlarge the hole more on the South end so it will end up larger. This will sharpen the D more than the E. Don’t worry about the D#. It should end up in tune as well.

As an aside, it has become popular, or even standard, to play the D by closing hole 3 and opening hole 4, just the way it is tuned, even when you are otherwise playing in mode 1. This is a hybrid scale, and obviously couldn’t be done on a 5 hole flute. I think the reason for this trend is that many six-hole flutes are tuned without paying attention to the cross-fingering, so that D is in tune with hole 4 open because it was specifically tuned that way, while the cross-fingered D may be out of tune. There’s no reason they can’t both be in tune, and this would allow the 5 hole players and the hybrid players to both play your flute without changing the fingerings they have learned.

Hole 6:

F:   
F:   
F#: 

Hole 6 is the octave note, F#, and its cross-fingered note is F. Theoretically, the F could be fingered as . However, this cross-fingering is difficult to tune. It is easier to tune F using the cross-fingering . I recommend tuning and playing the F with this fingering.

Tuning is the same procedure as the other holes, with the cross-fingered pattern as shown.

Tip: The octave note, F#, is hard to tune without making the cross-fingered note too sharp. It helps to place hole 6 a little smaller and farther North, and to undercut it quite a bit at the North end.

Detuning and Retuning

At this point, you should again check for drift in the notes you have tuned earlier. It is likely that at least some of the notes you tuned earlier will need a slight adjustment. Typically, the primary as well as cross-fingered notes will tend to get flatter as you tune the later holes. This gives you an opportunity to fine-tune the flute overall and adjust the difference between the primary and cross-fingered notes by further undercutting North or South.

One additional problem is that the fundamental () often goes flat. This can be adjusted by shortening the foot end. However, shortening the foot end might make the other notes sharper. There are two ways to overcome this:

1. You can start with a fundamental note that is sharp to begin with — perhaps 20 cents sharp — and hope it ends up in tune.
2. You can leave all the notes slightly flat in your initial pass through the flute, adjust the fundamental, and then retune the finger holes.

I like the first method, because the playing holes are measured from the foot, so the foot should be right to start with, not moved later.

Undercutting

Undercutting means burning or grinding the inside rim of the finger hole without enlarging the diameter of the hole as seen on the outside surface of the flute.

Cut-away image of an undercut finger hole

We usually use undercutting to “enlarge” a hole without actually enlarging the surface diameter. If the hole is already as large as you want it, but the note you are tuning is still flat, you can undercut the hole to sharpen the note. Undercutting is usually done under the North rim of the hole, because it has more effect than undercutting the South rim.

We can use undercutting to our advantage when tuning the cross-fingerings as well. First of all, if the hole is getting too big and the note is still flat, you may want to consider undercutting the hole instead of enlarging it. Similarly to the above procedure, if you want to raise the pitch of the cross-fingered note more than the primary note, undercut the South rim (and vice versa). Even if the hole is not too big, undercutting is useful if the discrepancy between the flatness of the primary and the cross-fingered note is large. For instance, if the cross-fingered note is getting very close to being in tune, but the primary note is still substantially flat, you can undercut on the North end. This has the effect of moving the hole North without enlarging it much. This will bring the primary note into tune, hopefully without making the cross-fingered note too sharp. Conversely, undercutting the South rim raises the pitch of the cross-fingered note more than the primary note. The differential effect that undercutting has on the pitch of the two notes seems to be even greater than just enlarging the North or South side of the hole, though the overall effect is less.

One final point: If the finger holes are initially placed too far South, you will wind up with large finger holes. Undercutting can only do so much, and the cross-fingered notes will end up being too sharp. Undercutting is best used for fine tuning the relative spacing between the top three holes or between the bottom three. If you want bigger holes, you can start with a larger bore or a thicker wall of the flute.

Addendum

One more very important tip that will take some experience to understand: I've noticed that when the primary note is still more than 50 cents flat, the cross-fingered note should be in the range of 75–100 cents flat. In other words, when you simply enlarge the hole, the cross-fingered note sharpens faster than the primary note, and it will catch up. If the primary and the cross-fingered notes are both 50 cents flat and you simply enlarge the hole, the cross-fingered note will overtake the primary note and end up at least 20 cents sharp. The moral of this story is: you can start adjusting even when the notes are more than 50 cents flat. If the cross-fingered note is not significantly flatter than the primary note, start adjusting the hole Northward. This will make sense when you start looking at the cross-fingered notes when you are tuning.

An example for clarity: when you figure out the ideal hole 2 size with FluteSheet and then figure the location for this hole size, it should come out just right just by enlarging the hole. But while you are tuning this second hole, you will notice that when the primary note is still 50 cents flat, the cross-fingered note is more like 75 cents or more flat. That's OK. Don't adjust the hole position. As you enlarge the hole, the cross-fingered note will “accelerate” and catch up with the primary note so that they will come into tune together just by enlarging the hole. Hole 3, on the other hand, tends to have a sharp cross-fingered note. It would tune more easily if it started farther North, but this would throw off the finger spacing. The solution is to calculate it a little farther North, partially tune it by enlarging, then when the primary note is still more than 50 cents flat, start tuning by undercutting the North side of the hole. This should slow down the cross-fingered note and bring the two notes in tune together. In practice, I slowly enlarge and undercut alternately while watching how fast the two notes are sharpening. If the cross-fingered note is catching up, I undercut North. If I want the cross-fingered note to catch up more, I enlarge the hole. If the cross-fingered note is too far behind, I undercut on the South side of the hole.

With practice, you get a mental picture of how much each note sharpens with enlarging, you'll see that the cross-fingered note sharpens faster than the primary note, and you’ll know when to start undercutting.