So you’ve managed to make a sound on the flute. Fantastic!! But now there’s more work to do! Your sound or ‘flute tone’ needs to be refined to become clear and focused. And this means for every note and over all dynamic ranges! Good flute tone is often one of those things kicked to the curb by beginners, simply in their excitement to learn new notes and start playing melodies. However, months or even years of playing without an understanding of what affects your flute tone will mean the musicality of your playing will suffer. You’ll be able to play the flute, but you won’t be able to play it beautifully.
In this article I’ll explain what is meant by flute tone and what major factors contribute to your flute’s unique ‘voice’. In my quick video below, I’ll show you how some simple mistakes could be sabotaging your flute tone and how to correct them.
What is meant by flute tone?
Flute tone or flute tone colour refers to the quality of sound a flute produces. In general, tone colour helps to distinguish different musical instruments apart, even if they play the same note at the same volume. It can go to a level deeper and is even used to describe the subtle differences of the same note played by two different flutists or by the same player on two different flutes. The flute player’s ability to modify the ‘voice’ of their flute helps to add expression and create a personalised performance of a piece of music. Just as if you were reading a fairy tale to a child and voicing different characters, your flute should be communicating a story to your audience (even if that audience is just you for now!).
How sound works in the flute
To understand flute tone colours we need to understand how sound is produced in the flute. The vibrating air inside the flute produces sound waves. The number of waves occurring each second is known as the frequency. High notes are produced by high frequency waves, and low notes are produced by low frequency waves. When we play a note, we are actually playing several note frequencies at set intervals from the original note (called overtones) all at once. This collection of frequencies is known as the harmonic series of each note.
These overtones are blended together so that we really only hear one dominant note (known as the fundamental). The differences in tone colour between musical instruments are due to characteristic combinations of overtones from this harmonic series. So is there a ‘perfect’ combination of overtones? The answer is not really because studies show we all have rather unique tone preferences. But overall, a note that either lacks the upper harmonics or has one harmonic that is overly excessive are considered the least pleasant for listeners.
Describing flute tone colours
You’ll hear lots of different words used to describe flute tone such as dark, bright, singing, rich, dull, airy… If you’ve done any reading on flute playing you’ll have come across a frustratingly large number of ways to describe tone. Playing with a variety of flute tone colours requires some imagination as well as player skill. Visualising the sounds as colours of the rainbow spectrum or by using emotive describing words (such as ethereal or veiled) can help players achieve some tone ‘personality’. The extremes of flute tone such as ‘breathy’ and ‘clear’ are relatively easy for listeners to distinguish. But some descriptions of flute tone are more subtle and require an ear that has been trained by listening to many examples of flute playing. As a general rule of thumb words such as dark or mellow describe sounds that are rich in the lower overtones. Bright, edgy and hard typically describe sounds that are rich in the higher overtones.
A study examining consistency of tone descriptors found that it’s a highly subjective area. Participants were given a series of long tone notes played by various flutists and simply asked to listen to and describe the quality of the sound without any guidance. Ten common descriptors were identified by the group. Some of the long tone notes played were easily categorised as either great quality (described as focused, clear and rich) or poor quality (described as unfocused, airy and weak). But other sample notes were far more difficult and showed a confusing mixture of tone descriptors by the participants. Interestingly, the more experienced flutists showed they preferred different tone colours to the student group.
A spectral analysis of the same note played by two players. The harmonic overtones within the note are represented by the coloured lines. The left note was judged as ‘poor’ quality by listeners and shows an imbalance of the upper and lower overtones and one excessive overtone. The right note shows a more even balance of all overtones and was judged as ‘great’ by listeners. Source: Yorita (2015)
How flute tone is affected
Subtle differences in flute tone colour can be modified by emphasising either the lowest or highest overtones. There are two major factors overall that contribute to the strength and number of these flute overtones
- The embouchure shape of the player; and
- The quality of the materials and cut of the embouchure hole itself.
The role of the embouchure in flute tone
The vertical and horizontal placement of the flute against your chin as well as the shape and size of your aperture are crucial to a well-formed embouchure. They influence the angle, distance and speed of air striking the embouchure hole, which are key factors in good tone production. Slow air speed favours lower overtones producing a darker, fuller sound. Faster air speed favours the higher overtones producing a brighter tone. Air directed at a shallow angle across the embouchure hole favours the higher overtones. Playing with different aspects of your embouchure is the primary way tone is influenced.
Resonance and flute tone
A resonator is a hollow cavity that vibrates with and amplifies sound waves. Essentially it acts as an echo chamber that adds volume and enhances the combination of overtones within a sound. The flute tube acts only as a partial resonator, meaning the body of the flutist must also act as one. The vibrating column of air that travels back and forward between the flute and the body’s resonators are responsible for sound production. The flutist’s largest resonator is the mouth and throat cavity. The position of the tongue, jaw, soft palate and cheeks are all factors that the flutist can control to influence its size and shape. The size of the resonator needed to produce the purest and most intense sound depends on the pitch of the note. Higher notes require smaller resonators and lower notes require larger resonators. Adjusting the size of these body resonators appropriate to the pitch of the note being played will produce a fullness to your sound over the entire note range.
The role of flute materials in flute tone
Flutes can be made from a vast array of metals and alloys that range significantly in price and quality. Many professional players swear that certain materials have very distinctive ‘tone colours.’ For example the tone of silver flutes is often described as bright whereas gold is described as warm and deep. Do more expensive flutes sound better? Most experienced players would say yes! But it’s difficult to pinpoint whether the improvement in sound is due to the higher quality materials used or the more precise craftsmanship of a handmade flute.
Studies to determine whether material really influences flute tone colour have been conducted. One such study tested whether experienced players and listeners could identify the material a flute was made of, and describe the tone of each. A passage of music was played by various players on flutes made from seven different materials. The sound spectrums were analysed and found no statistically significant difference in flute tone between the flutes played by each player. However, the sound spectrums differed greatly between players. This suggests that unique player factors (i.e. embouchure, breath control etc) are really responsible for flute tone colour. Once again, the tone descriptors used by the listeners often contradicted one another, showing the subjective nature of stereotypes players have of flute material types.
Experimenting with flute tone and resonance
Whatever your flute is made of and the playing level you’re at, your objective should always be to produce a sound that is pleasant to the listener. So take some time experimenting with aspects of your embouchure and note the changes in your tone. Play one note (such as a low G) for this exercise, close your eyes or record yourself and slowly work through making changes to
- The vertical and horizontal position of the flute
- The positioning of your arms
- The amount of lip coverage of the embouchure hole
- The length and depth of the aperture and
- The angle of the air jet by moving your jaw and/or lips back and forward.
- The speed of air
Finally, pick one of these flute tone colours that sounds the best to you (remember – focused, rich and clear). Can you match that same tone when playing higher or lower notes?
Next, you can attempt to enhance these different tones by playing around with the idea of resonance. Practise by forming the vowel sounds A-E-I-O-U, dropping your jaw, yawning with your mouth closed as you play to make changes to the shape and size of the throat cavity.
Have fun as you learn to make your flute ‘speak’
Wilcocks, G., Improving tone production on the flute with regards to embouchure, lip flexibility, vibrato and tone colour, as seen from a classical music perspective, in Department of Music. 2006, University of Pretoria.
Harby, K., UNSOUND REASONING. Scientific American, 1998. 278(3): p. 20-21.
Yorita, R. and J. Clements. Using spectral analysis to evaluate flute tone quality. in Proceedings of Meetings on Acoustics 169ASA. 2015. ASA.
Linortner, R. Wall material and the sound of the flute. [cited 2017 2 September]; Available from: http://iwk.mdw.ac.at/?page_id=97&sprache=2