In a previous article I described why I personally chose to learn the pennywhistle, and listed a number of resources that I used to select my whistle and that I am currently using to guide my initial study of the instrument. At the end of that article, I mentioned that the process of learning to play had revealed a number of surprises both about Pennywhistles themselves, and about the experience of learning to play an instrument.
This time around, I’ll cover the surprising technical aspects of the pennywhistle, and in an upcoming article, I’ll explain those experiential aspects of learning to play that have been (mostly pleasant) surprises.
If you’re an experienced whistler this will all be “old hat”, but if — like me — you’re just starting out, or you’re contemplating picking up the pennywhistle (a choice I’d highly recommend – it’s a whole lot of fun), perhaps you can avoid some of the problems described below, or find a better understanding as to why your whistle does what it does.
Playing the Pennywhistle is a lot harder than I thought!
The whistle is easy, right? Just pick it up and blow into it. Well … no! It doesn’t work that way. I guess it should have been obvious if one thinks about the physics of why a whistle does what it does. Without going into too much detail, a whistle works like this: Blowing into the mouthpiece (the fipple) causes a stream of air to rush past a slanted hole (the “labium”) such as the one you see in the picture of a whistle head below.
The head of pennywhistle showing the fipple and labium
The stream of air “breaks” over the edge of the blade, causing turbulence, which creates a number of constant air vibrations, or “sound waves”. Since there are many frequencies of vibration being produced this is called noise. The frequencies making up this noise depend on the speed of the stream of air flowing past the blade; this is an important fact in figuring out why your whistle does what it does.
Each “sound wave” has a frequency (The number of times per second that the “sound wave” reaches “maximum pressure”), and a wavelength (the amount of distance a wave takes when traveling to go from highest air pressure to lowest pressure and back to highest pressure). Here’s where the tube of a pennywhistle’s body comes in to play: If the wavelength of a particular frequency happens to “fit” inside the length of the air column evenly, then the wave starts to reinforce itself. Pulses of the “sound wave” of a particular frequency travel up and down the resonating air column, “stacking up” evenly and reinforcing each other. If the noise the fipple is producing contains the right frequency/wavelength for the length of the whistle, it suddenly gets a lot louder, and you hear a much louder pure tone called a pitch. We tend to hear the reinforced pitch and more-or-less ignore the other frequencies produced by the fipple as background noise, because the resonant pitch is so much louder and because that’s how our brains tend to process sound.
A resonating column of air, with the simplest resonance shown: One “standing wave” fits exactly in the length of the whistle’s body
We change the length of the “resonating air column” by opening and closing the finger holes on the tube. Open a hole, shorten the resonating air column, and you change the frequency of the tone that can “stack” inside the column. Provided that the noise being produced in the turbulence caused by the air stream flowing over the blade contains a frequency that will resonate in the whistle body’s air column, you hear the pitch of the whistle change. Close a hole, and the opposite happens: the air column lengthens, but only if you have closed the hole completely! Not quite getting the hole sealed properly can do odd things to the behavior of the resonating air column, and odd squeaks and false notes will be the result. (As an aside, it is possible to use this “odd behavior” to make whistles do things that they normally don’t do. This is what the techniques of cross-fingering and half-holing deal with, but they are advanced techniques that I havn’t experimented with yet, and thus can’t really comment on)
In reality, whistles are a little more complicated than this, as many whistles have a conical bore as opposed to a simple cylindrical bore, as a conical air column will produce the same fundamental frequency as an open cylinder of the same length and will also produce all harmonics. Still, understanding the basic physics of resonating cylindrical air columns will give you a “good enough” grasp on why your whistle does what it does.
Diagram of a conical bore, with the more complex standing waves that result
Breath control and posture
So what? How does this affect the practical aspects of whistle playing?
Well, given the physics above, it seems obvious that a steady, constant, non-turbulent flow of air past the blade in the fipple is a requirement for the pitch to remain constant.
Practically, this means that you have to learn to blow steadily, with constant pressure, and without air turbulence in your air stream. How hard can that be, right? You’d be surprised! It isn’t really hard but it does take some attention. Sit up straight! Hold your whistle properly! Breathe with your diaphragm! Work on that lung capacity! What did I tell you about constant air pressure?! Welcome to Whistle Boot Camp.
Seriously, sitting up straight means that the air does not have to flow around any “bends” in your airway which is what it would have to do if you put your chin close to your chest or threw your head back. Air flowing around “bends” may introduce turbulence, as air traveling along the outside of the bend has to travel further and faster than air flowing along the inside of the bend. If this speed difference is too great, the laminar flow of the airstream is broken, and turbulence occurs, which can throw the sound of your whistle off as the turbulence in the air stream mixes with the turbulence caused by the fipple’s blade, and changes the frequencies present in the “noise”. Likewise, holding the whistle straight out ahead of you, at about a 45-degree slant, means that the flow of air through the body of the whistle is “in line” with the flow of air coming out of your mouth, and there is no chance of inducing unwanted turbulence. You can experiment with this: blow a low steady note, then move your whistle up and down, back and forth. Tilt your head up and down. Slouch down in your chair. While you are doing this pay attention to the note coming out of your whistle. While the whistle will forgive some variation, there will come a time when you notice that there are jarring harmonics creeping into the note as more and more air turbulence is introduced into the air stream. Likewise, experimenting with ways of breathing (shallow lung based, deep breathing from the diaphragm, etc.) will quickly show that deep diaphragm breathing and some breath control will make blowing a steady stream of air much easier.
Not all that difficult, but a little attention and care will go a long way to producing nice clean pitches and reduce the number of unwanted squeaks and other noise artifacts when jumping from note to note.
Remember that the frequencies being produced in the noise depend on the speed of the airflow past the blade, and that to produce a specific pitch you have to have that frequency “inside” the noise? This means that every note that you want to play on a pennywhistle has a different optimum airspeed. This means that not only does each note have a fingering combination, you have to blow with the right amount of air pressure (which regulates the speed of the airflow). It isn’t as bad as it might be; remember that the noise produced by the fipple contains many different frequencies. This means that if you change the length of the air column by opening or closing one hole, there’s a good chance that the frequency that the new length of air column “needs” to produce a pitch is already present in the “noise”. Thus I’ve noticed that there are blocks of notes which all can “accept” the same amount of pressure and still produce a pure tone. I’ve dubbed these “dynamic blocks”.
For example (on my whistle, which is tuned to high D) I can blow with the same force for the note produced by opening the bottom hole and the note produced by opening the bottom two holes, but I have to blow a little bit harder for the note produced with three open holes. Likewise there are many other clusters of notes which require their own amount of “blowing force”.
You can experiment with this as well. Blow with a constant low pressure and move up the scale. Eventually you’ll notice that notes go flat, or sound “squeaky” as they start to “need” frequencies which you’re just not providing. You can also play with individual notes: keep a constant fingering pattern and experiment with blowing harder and softer, finding the range of pressure that the pitch will accept, and where it sounds best.
Octave jumps and embouchure
Here’s one of the things that I find really “neat” about the pennywhistle; you can jump whole octaves, just by learning how to blow.
Remember that different notes require different resonances in the air column, and therefore different speeds of airflow? Well, there can be multiple resonant frequencies for a given column of air! Seems obvious if you think about it. If one wavelength of vibration will “fit” inside a resonating column of air, so will twice that wavelength – it just takes twice as many “standing waves” to fit in the column. So it is with the pennywhistle: if you blow fast enough to set up twice the resonance frequency within the air column, you also get a nice pure pitch.
A cylindrical body, showing a representation of how standing waves of different wavelengths (wavelengths which are multiples of each other) will fit in the same resonating air column
While this technique is sometimes called “overblowing” you don’t actually blow with any more force. Instead you change the shape that your lips make around the mouthpiece, making the “O” formed by your lips smaller. According to fluid dynamics (and air is considered a fluid for this purpose), if you constrict the flow of a fluid stream, then its pressure and speed go up. You’ve seen something exactly like this if you’ve ever played with the garden hose as a kid: putting your thumb over the end of the hose constricts the size of the opening the water flows through, making the pressure go up, the water travel faster and thus much farther, and you can spray your little sister with water. How you change the shape of your lips and the airflow characteristics is referred to as embouchure. Remember that when you change the airspeed, you change the frequencies produced by the fipple? By overblowing the right amount, you can create the right frequencies for a whole different set of pitches that will resonate in the air column of the whistle’s body, for a given fingering pattern (as an aside, and to head off disdainful comments from concert flautists, the complexity of the embouchure techniques open to whistlers pales in comparison to the vast amount of embouchure control possible with the western concert flute).
Presto, you just added a second octave to an instrument with only 8 notes! Theoretically, you could keep doing this, increasing the rate of air flow, hitting higher and higher octaves, as shown in the diagram above. In practice whistles are imperfect creatures, and few whistles are tuned well enough to overblow more than one additional octave. Apparently the Sweetheart Professional can “overblow” into a third octave cleanly, and I’m sure there are other “high end” whistles that can, but these are extremely well made (and expensive) instruments. Your “run of the mill” pennywhistle probably won’t do this (mine will, but there are overtones that hurt and the tones are just a tad sharp).
Jumping from “Block to Block”
The whole idea of “dynamic blocks” is more than merely interesting (to some, I guess) theory; it has real practical considerations when you play. You must learn and remember how hard to blow for the note you want to play, and learn how to “leap” from block to block cleanly. Notes in a given piece may jump up and down rapidly, and blowing too hard, or too soft for your “target block” can cause notes to go flat, or have unpleasant overtones and squeaks accompany them.
For example, The Minstrel Boy is a very traditional Irish Air which incorporates a fair amount of “jumping around” including one sequence where the fingering remains the same and one switches from overblowing the second octave to blowing the first octave. Peg Ryan’s Polka is another tune in which there is a lot of staccato “jumping around”. Knowing how to successfully, and cleanly, change the force of one’s blowing is invaluable if one wishes to avoid false notes. Personally, I’ve found that if the tune will accommodate it that tonguing (a form of ornamentation described below) is very useful in cleanly breaking the air flow and allowing you time to change the pressure/speed of the airflow without “slurring” the notes.
Ornamentation and Dynamics
The Pennywhistle is a monophonic instrument that can only play one note at a time: there are no chords, or any but illusory harmonizations possible with a single pennywhistle. Nor does the pennywhistle seem to be capable of the embouchure multiphonics available to the concert flute. Personal artistic expression of the whistler has to come through variations in tempo, rhythm, the “attack” of the note, and ornamentation. Unsurprisingly, as the pennywhistle shares the same harmonic limitations that the bagpipe has (and the whistle doesn’t even have drones – which you may view either as a drawback, or as a blessing), the ornamentation techniques that create simple harmonics, musical embellishment, and the personal expression of the musician, are very similar.
Instead of playing multiple notes simultaneously pipers and whistlers tend to play multiple notes in such a rapid succession, and in particular patterns, as to make them appear to be blended in the ear of the listener. This is called artificial polyphony. These quick notes are also called grace notes, and while they don’t often create the illusion of an actual chord, they tend to alter the perception of a given pitch, so that two sequential pitches of the same frequency seem to have distinct existence, and to have a different texture or timbre.
Typical whistle ornaments include strikes (where the pitch above the “base note” is sounded very briefly), cuts (where the pitch blow the “base note” is sounded very briefly), rolls (a strike, the base note, and a cut played in very rapid succession – followed by a sustained base note), cranns (like a roll, only using the pattern strike-base-strike-base with no cut), slides (where an adjacent note is played and then a finger hole slowly opened or closed to “slur” into the target note), and tonguing (where the tip of the tongue is touched to the back of one’s teeth in an unvoiced T, creating a “gap” in the airflow and the sound, breaking two notes cleanly into distinct sounds).
Apart from requiring a whistler to develop a fair amount of manual dexterity (I’m just learning the basics of ornamentation), it might be wise to remember that the “grace notes” might be affected by how hard you are blowing. This is especially true with tonguing, where releasing the hold can result in a slight “puff” of air. Depending on what ornamentation you are attempting, you may find that you have to adjust your blowing to pull off the combination, or perhaps choose an alternate form of ornamentation (identical — or similar — effects can often be accomplished with different ornamentation: strikes v.s. cuts, for example).
For example, there is a point in Peg Ryan’s Polka where the note sequence drops from one “dynamic block” to one that requires lower pressure, where there are two notes in rapid succession that have the same pitch. Since I’ve just been blowing harder, I tend to be blowing at the upper range of what is “acceptable” to produce the required resonant frequency for that pitch. Because of the quick staccato rhythm of a polka, it is tempting to use tonguing to give the notes a nice crisp staccato “attack”. However, trying to separate the two notes by tonguing results in a small spike in the pressure, pushing the air pressure above what that “dynamic block” requires and there is a loud squeak! Once I figured out what was happening and why, I switched to a cut to break up the notes, and the piece sounds much better now.
But it’s not all physics!
While I’ve been discussing the physics of Pennywhistles, why they work the way they do, and how understanding the physics helps me to figure out how to make the whistle do what I want (and I hope it helps you as well), don’t lose track of the fact that whistling is not about the physics! Playing the Pennywhistle is about making music, personal expression, and above all having fun doing it.
The experiential and expressive side of learning to play the Pennywhistle has also had it’s own surprises. I’ve learned that traditional Irish music is both much simpler than you might think, and yet has the potential to be woven into much more complicated forms. I’ve learned that listening to your intuition can vastly improve your playing, and that the “maverick” part of your brain can cause you to make “mistakes” that are actually improvements. I’ve learned that listening is a critical skill in learning to play – especially listening to yourself. I’ve also learned that playing an instrument, and studying a martial art, have a great deal in common (although I doubt there are any practitioners of Shakuhachi-jitsu out there).
All aspects that I’ll cover next time.
This article is part of an (informal) series on the Pennywhistle. If you found this article interesting you may be interested in Picking up the Pennywhistle and (the upcoming) Experiencing the Pennywhistle.