As I mentioned last column, I spent last week singing with the Canadian Chamber Choir in southern Ontario. In addition to concerts, we also took part in several workshops with musicians ranging in age from eight to 80.
Our director, Dr. Julia Davids, who teaches and conducts choirs at Loyola University in Chicago, would usually lead workshop participants through the same vocal warm up she used with the choir. During that time, one question she liked to ask was “What’s the equation for singing?” In other words, if x + y = “singing,” what are x and y? The answer: “breath” and “space.”
Which got me thinking, naturally, about the science of singing.
Breath has to be part of the singing equation because air must be expelled for a sound to be made—and before you expel any air, you first have to suck some in. The diaphragm, the muscle between our lungs and the lower abdominal cavity, is pulled down, which lowers the air pressure inside the chest cavity and causes air to flow into the lungs.
As the diaphragm relaxes, the lungs release air. How forcefully that happens helps determine the volume and duration of the sound produced.
Sound waves are generated by vibrating objects, so to sing, you also need to make something vibrate. Phonation, as sound generation is called, happens in the larynx, a muscular tube that contains two folds of mucous membrane, the vocal folds, with a gap between them, the glottis. Each fold encloses an elastic vocal ligament.
In normal breathing these ligaments are slack, allowing air to pass silently in and out through the wide-open glottis. To produce a sound, muscles tighten the ligaments. As air is forced through the now much narrower glottis, it causes the vocal folds to vibrate. The tighter the muscles contract the vocal folds, the higher the pitch.
The second part of Dr. Davids’s equation for singing, space, is necessary to allow resonance, which amplifies the sounds. As the sound waves generated by the vibrating vocal folds enter the various spaces inside the head and body, they cause the walls of those chambers to also vibrate at various related frequencies.
Finally, words are produced through articulation, complex maneuvers with the lips, tongue and soft palate of the mouth, and of related facial muscles. In choral singing articulation is particularly important because everyone needs to be singing the same vowel sounds and consonants. Last week, we sometimes spent several minutes at a time focusing on the precise sound and placement of two or three fleeting consonants in a four-minute piece.
That’s the science of singing in a nutshell. But some singing you’re indifferent to, or actively dislike, while some enthralls you. Is there some additional science behind beautiful singing?
In 1993 Clayne W. Robison, a voice professor at Brigham Young University, conducted a study in which recordings of classically trained baritones and female pop singers were ranked in terms of beauty by a 13-member panel made up of noted voice teachers and scientists and classical music connoisseurs.
Robison then re-examined the recordings to determine what the most voices ranked as most beautiful had in common, and found that beautiful singing includes the presence and evenness of vibrato, “cleanness”—no out-of-tune overtones—and most importantly, a mixture of bright and dark resonances.
For Robison, the dark resonances are most important. More properly called tracheal resonance, this resonance occurs in the trachea behind the chest: a singer feels it as a kind of faint buzzing. The Italians call it appoggio, or “breath leaning against the chest.” It adds depth and feeling to a singer’s voice, while the bright resonances, the ones arising from the vocal folds through the pharynx right up to the lips and tongue, add clarity and a speech-like naturalness to the sound.
The best way to get that all-important tracheal resonance, and keep it properly blended with the bright resonances?
Correct posture and free breathing, says Robison: or, in other words, Dr. Davids’s “space plus breath.”
Singing may be an art, but it’s based entirely on physics.
Which is great for a science-minded singer like me. I actually like equations.