My generation grew up thinking that the The Wizard of Oz was entirely in black and white. When we bought our first color TV, we realized the dreary sepia of Kansas gave way to an explosion of color when Dorothy stepped into Oz. The filmmakers made an artistic decision to use both black and white and color, enhancing the contrast between Dorothy’s mundane life and her dream world.
A similar transformation takes place when a young flutist expands a monotone into a rainbow of tone colors, becoming a true artist. Let’s take a look at what tone color is, how we manipulate it, and how tone color relates to dynamics, projection, and style.
Teachers often speak of color only in vague, subjective, and contradictory terms and fail to explain precisely how to vary it. The most common adjectives, bright and dark, can mean opposite things to different musicians. For instance, some use dark to describe a rich and sonorous tone while others use it for a hollow tone.
Tone Color Defined
Tone color or timbre is “the quality given to a sound by its overtones.”1 A common experiment that Trevor Wye describes in his Practice Book for the Flute, Volume 4: Intonation proves that any musical tone consists of its fundamental (the pitch we play) and a series of overtones:
On the piano, silently depress any key corresponding to an overtone, and then play a loud, staccato middle C. The overtone rings sympathetically with the fundamental. These overtones have a simple relation to the fundamental: the octave or second overtone has twice its frequency, the third overtone three times, etc. The overtones are then known as harmonics.
Tone color helps the ear identify a particular instrument, as each instrument has a characteristic pattern of overtones. For instance, the oboe is weak in the fundamental but much richer in overtones than the flute, while the clarinet has a unique combination of overtones, with a nearly absent second harmonic in some of its range and generally strong in the odd-numbered harmonics.
Typical timbre on the flute changes with register: in the low register the fundamental is relatively weak and the harmonics are strong; the middle register has a balance between fundamental and harmonics; and in the upper register, the fundamental is dominant and harmonics are weak. 2
A sound without overtones is open, pure, hollow, and sometimes dull; the French have two wonderful words for this, détimbré (uncolored) or naturelle, 3 and Trevor Wye calls this the Yellow Tone. A sound with overtones is full, rich, brilliant, and sometimes harsh; the French call this pénétrante, and Trevor Wye calls it the Purple Tone.4
Teaching Tone Color
Each flutist has a unique customary color due to physical attributes, such as size and shape of the mouth and lips; conception of sound (we naturally play with the tone we perceive to be the best); and the qualities of the particular flute. The third factor has less effect than the first two; several flutists playing the same instrument can sound more different from each other than one flutist playing various flutes.
A good teacher encourages students to discover their own sounds within the limits of good taste. Young flutists should listen to many different professionals instead of modeling their sounds on one. Too often an influential player has produced a generation of imitators. The trend over the past century has been to abandon the détimbré (with few harmonics) color in favor of the penetrating one, and some current flutists never diverge from brilliance. Some flute makers have contributed to this trend by designing flutes that bring out the upper partials.
Our goal should be to have control over an array of colors and use them wisely. Some suggest experimenting with various vowels, and obviously ee sounds more brilliant than a vowel such as ah or oh. The differences in flute tone are subtle. Another variable is the lip opening: a round shape makes the tone more pure, while an ellipse contributes more harmonics.
The biggest change in color results from varying the blowing angle and airspeed, or as John Coltman writes, “Jet offset combined with blowing pressure seems to be the dominant variable under the control of the player in shaping tone quality and dynamics.”5 A steep blowing angle combined with higher blowing pressure produces more harmonics.
I manipulate tone color with the upper lip. A relaxed upper lip results in the uncolored sound, and a firm upper lip that directs the air downwards results in a more penetrating sound. You can see the difference in tone with a spectrum analyzer, which displays various frequencies within a sound. Many are inexpensive.6
Frequency is a way of measuring pitch in cycles per second, or Hertz. The flute’s basic range is from 247 Hz (low B) through 2349 Hz (high D). The following, a screen shot from the spectrum analyzer in the recording software Amadeus Pro, illustrates a détimbré color; the fundamental, A-440, is clearly dominant, and the harmonics are weak.
Contrasting with the first example, the following shows the same note played with a penetrating color; the harmonics are much stronger.
At first some students have trouble hearing or bringing out these differences, but visual feedback enhances their sensitivity and control. Once they can distinguish and manipulate colors, practice using them on different tunes, starting with “The Aquarium” from Saint-Saens’ Carnival of the Animals for pure tone and a theme from Ravel’s Introduction and Allegro for brilliant tone, both of which can be found in Trevor Wye’s Tone Book.7
One challenge is keeping the color consistent from one note to the next. As we have seen, the harmonic content of the flute sound changes between registers, and the changing length of the tube within each register colors the sound as well. Nevertheless, it is possible to minimize color changes between adjacent notes. Marcel Moyse designed this exercise to practice homogeneous sound:8
When practicing it, listen closely for matching colors. Using a spectrum analyzer will make you more sensitive to tone quality.
Wide intervals require particular attention when working on color matching. In an ascending leap, prepare the greater brilliance of the high note with a penetrating tone on the low note, as in this passage from Mozart’s G Major Concerto:
Artistry of Tone Color
The next step is deciding where to use different colors. In general, modern music requires more brilliance, and Baroque and Classical music call for a sweeter tone, closer to that of the wooden flute. In tonal music, tone color should reflect harmony and key. Bach’s cantatas and Mozart’s operas show a consistent association between certain keys and specific emotions and moods in the text. Theoretical writings by Charpentier, Kirnberger, Mattheson, Rousseau, and Schubert also directly connect keys to affections. For instance, begin Bach’s Sonata, BWV 1034 with a tone rich in harmonics to reflect the tragic implications of E minor.
Later, when the same theme occurs in G major – a gentle, idyllic, and peaceful key – play with fewer harmonics.
The third movement of this sonata is the reverse: it starts in G major, requiring a gentle tone, and the middle section modulates to E minor and B minor, calling for a richer sound.
Since Debussy, French composers treat harmony more coloristically than functionally, and their music cries out for a wide array of colors. A contrast in color is especially effective to underline a chromatic inflection as in this passage of the Hüe Fantasie.
Many players use tone color to enhance dynamics. For instance, a timbral change is effective in the following passage from the Griffes Poem.
Contrarily, I normally use color in the opposite way. I add a little brilliance to compensate for the flute’s tendency to sound dull in soft dynamics and use an open sound to prevent shrillness in loud dynamics.
Blending and Projecting
Flutists should learn to adjust color according to their role as a soloist or an ensemble player. A brilliant tone attracts more attention.
A complex and much debated question is the role of tone color in projection, or the ability to be heard at a distance as distinct from others in an ensemble or an accompaniment. As every experienced flutist knows, the flute sounds much different to an audience than it does to the player. I have heard a former principal player of a major orchestra sound disconcertingly diffuse up close but project marvelously. Some players who use a lot of edge cannot be heard at a distance, but those who play without many upper partials also do not project.
One factor is room acoustics. Different halls emphasize different frequencies, so a tone that projects well in one setting may not in another. You should always ask a knowledgeable listener whether a certain sound carries.
Research contradicts the common assumption that the fundamental projects better than the overtones. For the sound waves coming directly to the listener’s ear, the intensities of all the frequencies in the flute range fall off nearly at the same rate with distance. In a concert hall, higher frequencies in the indirect sound may be absorbed more than lower ones, so the performers may want to emphasize these to correct for the loss. Furthermore, listeners can infer the fundamental from harmonics: “For fundamental frequencies up to 500 Hz, the third, fourth, and fifth harmonics when present are especially important. They are often even more important than the fundamental itself, which can be completely absent without changing the perceived pitch.”9
A listener’s heightened sensitivity to pitches in specific registers determines how well a flute tone is heard at a distance. “The higher harmonics make the note sound louder partly because they add extra power to the sound wave, but also because our ears become more sensitive as the frequency increases with increasing frequency.”10 Dr. Neville Fletcher, a physicist with a distinguished history of writings on flute acoustics, wrote, “I would guess that ‘projection’ is maximized when the strength of the harmonics between about 1000 and 3000 Hz is maximized. This will give a particular characteristic tone color to the flute sound.”11 The audience will hear a flutist more clearly when the flute tone contains a rich mix of fundamental and harmonics in the ear’s most sensitive range .
Trained musicians can identify a particular flutist on recordings because each player has a distinctive characteristic timbre. However, we should not become so attached to a particular sound that it never varies. Dare to employ a range of colors, even one that is as dull as Dorothy’s Kansas, which is effective in context. In conjunction with changes in volume and vibrato, tone color provides a powerful expressive tool. Not every musician will use the same color in the same passage, but Vive la difference!
1“Timbre,” Merriam-Webster Online Dictionary, http://www.merriam-webster.com/dictionary/timbre (accessed May 25, 2009).
2 Neville H. Fletcher, “Acoustical Correlates of Flute Performance Technique,” Journal of the Acoustical Society of America 57/no. 1 (January 1975)” 235-236.
3 Angeleita S. Floyd, The Gilbert Legacy: Methods, Exercises and Techniques for the Flutist (Cedar Falls, Iowa: Winzer Press, 1990), 87-88.
4 Trevor Wye, Proper Flute Playing: A Companion to the Practice Books (Borough Green, Sevnoaks, Kent: Novello & Company Limited, 1988), 18.
5 John W. Coltman, “Jet Offset, Harmonic Content, and Warble in the Flute,” Journal of the Acoustical Society of America 120/no. 4 (October 2006): 2319.
6 See the Shareware Music Machine http://www.hitsquad.com/smm (accessed May 25, 2009).
7 Trevor Wye, A Trevor Wye Practice Book for the Flute, Volume 1: Tone (Borough Green, Sevnoaks, Kent: 1980), 9-10.
8 Marcel Moyse, De la Sonorité: art et technique (Paris: Alphonse Leduc, 1934), 3-9.
9 Donald E. Hall, Musical Acoustics, 3rd ed. (Pacific Grove, Cal.: Brooks/Cole, 2002), 403.
10 Joe Wolfe, “Loudness and Spectra,” University of New South Wales, http://www.phys.unsw.edu.au/jw/loudness.htmml (accessed May 25, 2009)
11 Neville Fletcher, email message to author, May 21, 2009. See his many publications at http://www.phys.unsw.edu.au/music/people/fletcher.html (accessed May 25, 2009).