Although few people are aware of this, it is possible to sing more than one tone at a time — to, in effect, sing harmony with yourself. This fact runs counter to most people's experiences, but nonetheless, if you know how to do it, you can produce multiple tones with your voice.

The techniques required can take time to master, but the physics involved is simple. It's based on the use of overtones, or harmonics, those higher and less audible, but still very important, tones that contribute to the overall "flavor" of your voice (or of any musical instrument, for that matter). The fact is, whenever you sing a tone, there are also a number of higher overtones "inside" that tone which are harmonically related to the main pitch (or fundamental tone) that you're singing. As I'll show you, you can physically "focus" your voice so that one or more of those overtones are emphasized, creating the impression that more than one voice is singing.

To focus your voice in this manner, there are two main concepts to work with: placement, and formants. Both have to do with controlling acoustic resonance in your body.

Placement deals with what part of your body is resonating the tone(s) you're singing, i.e. your chest, your throat, your head, etc. For our purposes, you want to use what's called "forward placement." That is, you want your voice to resonate in the front of your face — in your nose, cheekbones, and teeth. To learn to place your voice forward, sing a long sustained tone, such as an "oo," preferably a higher pitch in your vocal range, as these are more easily resonated in the head. See if you can focus the tone in such a way that you begin to feel a buzzing sensation in the front of your face. As you begin to feel it, emphasize it further by increasing the forward focus of your tone. It's a phenomenon better introduced in person than in writing, but if you play with it for a while, you'll get the hang of it. (TIP: You can test whether you're achieving good forward placement by touching your front teeth together very slightly; if they buzz strongly against each other as you sing, you're on the right track.)

By the way, singing with forward placement doesn't mean that the rest of your body isn't also resonating and contributing to the sound — it is. Forward placement just means that the "leading edge" of your voice is resonating and buzzing in the front of your face. You need this resonance because it means the higher harmonics are strong, and ripe for being made stronger.

To make those harmonics stronger, we now turn to formants, the characteristic frequencies and resonances of the different vowel sounds that we produce when we talk or sing. How do we produce these different vowels? By changing the shape of our mouths — both internally (through the relationship between the tongue and the roof of the mouth) and externally (the size and shape of the opening of the lips).

This is exactly the same mechanism we will use to sing overtones, but we're going to slow the whole thing down so that we can minutely control the changes in vocal resonance. Start by singing a long open tone, and very gradually alter the vowel sound that you produce. For example, start with an "oo" sound and very slowly "morph" it into an "uh," then an "ah," than an "a," then an "ee," etc. Find those odd, in-between sounds halfway between "ee" and "oo," or "ah" and "uh." Explore all the subtle vowel gradations such as you find in words like "wood," "car," and "oil." Don't just read these exercises, try them for yourself — they're fun, and quite ear-opening. As you experiment, notice the many ways in which you use your tongue and lips, and how they contribute to the sound.

I find it easiest to produce overtones while singing a vowel somewhere between "oo" and "ee" (another good one is a sound halfway between "oh" and "ah"). Again, forward placement is critical to create the focused "edge" that you need. When you feel that vibrating edge, very slowly make subtle changes in the shape and height of your tongue, and listen closely for the presence of high, bell-like tones in your voice. Keep making slow, subtle changes in your vowel sound and forward placement until you hear one of those tones. When you do, focus your attention on it, and see if you can increase its intensity, either by changing your tongue slightly and/or changing the shape/size of your lip opening.

Learning these skills is always a process of trial and error. It's important to pay close attention, listening for and emphasizing those subtle physical changes that produce the desired results. Only such gradual changes and concentrated attention will allow you to focus your voice precisely enough to begin amplifying specific overtones.

It's best to do these experiments indoors rather than outdoors, because the overtones are quickly carried away and lost in the open air. The space you sing in can have little or no ambient reverberation, like a car or small carpeted room, or it can be very "live," like a tiled bathroom, large open living room, gymnasium or dance rehearsal space.

Once you've got the hang of it, you can find and amplify a nice clear overtone for pretty much any vowel sound (though some are certainly harder, such as long "a"). Once you've found one overtone, if you keep your tongue position constant, you can produce other overtones simply by changing the size and shape of your lip opening. As you cycle up and down through the other overtones, it sounds much like the arpeggio of a chord because, as I said earlier, the overtones are harmonically related, both to the fundamental tone and to each other. Some singers are so skilled at singing overtones that they can actually sing several at once, enabling them to sing chords! One especially refined example of this can be found in the vocal tradition known as Tuvan throat singing. A contemporary example is the Harmonic Choir.

When I sing in this way, I often find myself singing longer and longer tones, as my breath capacity increases and I lose myself in the experience. Sometimes, I even feel as though I'm breathing in as I sing rather than out — a very restful and meditative state. Others who are listening often have the sensation that the overtones are not coming from the singer, but from another direction entirely, sometimes from all directions at once.

Give it a try and see what fascinating new sounds you can create. Enjoy!


Copyright 2001 by Richard Middleton.
All rights reserved.