Have you ever noticed that sometimes sound from your trumpet stops when you try to play a higher pitch? This article explains why this happens and what you can do about it.
Sound is vibration of air molecules, and playing the trumpet involves vibrating air with your lips and air stream.
The pitch of sound is the highness or lowness of sound played on the trumpet. Higher notes have higher pitches, and higher pitches have higher frequencies of vibrating air molecules. That means they vibrate faster.
To play higher pitches on the trumpet requires increasing the vibration of air through your lips. This is done by increasing the velocity of air blown through your lips. As the air velocity increases, the air molecules at the lips vibrate faster and the pitch rises.
Air velocity should not be confused with air volume. Blowing through the horn faster and harder moves more air through your lips but not necessarily at a higher pitch. For example, play a G in the staff softly then gradually play the note louder and louder. You are moving more air faster through your lips, but the note is the same. This is because the volume of air is changing the volume of the sound not the pitch.
To change the pitch, the air must move faster through the lips, but the lips must also vibrate faster in order to raise the pitch. To increase lip vibration, the lips must be pressed together to form a narrowed aperture or opening. A smaller hole increases vibration frequency, which raises the pitch.
Pressing the lips together can be done vertically or horizontally or both. A horizontal pressure creates an aperture with puckered lips. This involves drawing in the corners of your mouth toward the center as your lips pucker outward. When you reach your limit of drawing your lips into a tight circle, then its time to focus on pushing the bottom lip into the top lip to squeeze the aperture tighter and narrower.
As the lips narrow and tighten the aperture, resistance to air flow increases. Thus, to keep air flowing through your lips requires compressing the air. The narrower and tighter your lips press together, the more air needs to be compressed to push through your lips.
Air flows through the lips like water, but it is a gas, so it can be compressed. As you play higher notes on your trumpet, the escape valve (which is your lips) for the air becomes more difficult to pass through. So, instead of passing through your lips, the air compresses in your mouth, throat, and lungs. The air is not pushed through the lips, and there is no sound. Without sufficient air compression, the air will stop flowing through your lips, and your buzz will stop. Until there is sufficient air pressure to push through the narrowed lips, there is no sound.
Increasing air compression to increase your pitch requires compressing air in your lungs, throat, and mouth. This is your air column. If your diaphragm, throat, and tongue muscles are too relaxed, air will not compress sufficiently to be forced through your lips. To increase air compression from lungs to mouth requires narrowing your air column, which means squeezing the air in your lungs with your diaphragm muscle and narrowing your throat and mouth cavities by expanding your tongue muscle. For some who play really high notes, they use their arms to press on the sides of their rib cage to help narrow their air column and increase air pressure. If you let your cheeks blow out, then you lose air compression. Compressing air in your body requires making your air column from lungs to mouth smaller. The greater the air compression you can achieve, the greater your air pressure will be to push through a narrower aperture to produce higher pitches.
To experience the combination of lip aperture and air pressure needed to produce sound, buzz your lips at the lowest possible pitch. This is the point of minimum lip constriction and minimum amount of air compression needed to buzz the lips. Continue buzzing, and raise the pitch chromatically up to the next octave. Notice that without a combined effort to narrow the aperture of the lips with an increase in air pressure, you lose your buzz and sound.
Playing chromatically up and down the scale with just your lips buzzing (no mouth piece or trumpet) is a good exercise to train yourself to coordinate air compression technique with lip aperture constriction. And instead of pulling your lips back into a grin to tighten them, push them forward into a pucker. Also, try expanding your tongue to help compress the air while you increase your pitch. This will also help stabilize your jaw and lips for more control of the pitch. Try buzzing a major scale and arpeggios too.
There are two noticeable nodes of transition that will be most difficult to buzz. These are the pitch intervals to concentrate on. At the lower pitch, your lips make a transition from flapping to buzzing. The higher node of transition turns into a squeak. Play your scales from lip-flapping your lowest pitch to squeaking out your highest pitch with your lips pushed forward in a pucker while controlling the compression of air with your diaphragm and tongue. For the squeak, you will need to focus on pushing your bottom lip into the upper lip. Your body will feel very relaxed at the lowest pitch and tightly compressed at the highest pitch trying to squeeze air through your lips.
As you buzz or play scales, focus on your air flow to achieve a steady air stream pushing through your lips. The lips cannot buzz themselves. The lips can tighten to help determine the pitch as the air flows through them. But it is the air flow that ultimately causes the lips to buzz and produce sound. Focusing on the lips will tighten them, but without sufficient air stream there will be no sound. Think about air compression in your air column to maintain a steady, smooth air flow at all pitches.
Also, read, “The glottis problem” to find out how to overcome your body’s natural tendency to shut down your airway.
Glossary of terms
- Aperture is the hole formed by your lips through which air flows.
- Embouchure is the position of lips, teeth, and tongue when producing a sound through brass instruments.
- Note is the name of a tone.
- Pitch is the highness or lowness of a sound.
- Sound is vibration of air molecules.
- Timbre is the sound quality of combined pitches produced by an instrument.
- Tone is the single pitch of a sound.
- Velocity is the speed at which air flows.
