The Physics Behind A Clarinet and It’s Reed: It’s More Than Just Blowing Molly Risko Physics 001 Project 2 Background Information- The Clarinet • Johann Christopher Denner founded the clarinet in 1690. • Is a single-reed woodwind musical instrument that evolved from the first reed instrument, a chalumeau. • The difference between the two is two extra finger holes and a increase in range by two octaves. Music Terms to Know • An octave is a group of eight notes that are within the interval of two notes. In physics, it has either half or twice the frequency of vibration as the other. • A reed is a thin strip of material which vibrates to create music. A reed functions as an oscillating valve. • Resonance is the intensification of a sound or tone produced by vibrations. • Tones are regular, evenly spaced out waves in the air. How differently spaced out the waves are effects the pitch of a note. The more frequent a wave occurs, the higher the pitch (hence the frequency). Physics Terms to Know • Frequency is the number of complete cycles of a periodic process occur per a period of time. • As seen with tones, there is spacing between each waves. The length of this is called the wavelength. • Hertz is the unit of measurement to measure sound. It measures wave peak per second. • An oscillation, such as what a reed creates, is a cycle of fluctuation or change between states. • A sinusoidal wave is a sound wave shaped like a sine wave. How It All Comes Together • Clarinetists need to find the correct reed and pressure to apply to make terrific sounding music. A springy or flimsy reed will oscillate on its own creating a squeak…. Not exactly what the audience wants to hear. The air in the clarinet and the vibrations caused by the reed both control each other. • Sound is produced through an oscillating motion. This is what the reed functions as. The reed, as well as resonances in the air create oscillations in flow and pressure. The air in clarinet begins to vibrate causing sound to erupt out of open key holes and the bell at the bottom of the instrument. • Energy is used by the player to sustain a note as friction is lost within the clarinet and its walls. The Reed and Air Flow • Now, how exactly would a tiny piece of material control air flow and sound? Look at the chart below. Between the reed and the mouthpiece there is a tiny space. As seen below, as a player begins to apply pressure, there is more steady air flow. But as pressure increases the reed bends slightly, causing the gap between the reed and mouthpiece to decrease. Eventually the gap will close completely. This leads to air flow of zero. Pressure and Sound p represent piano in music or soft sounding. mf represents mezzo- forte, or medium loud. ff is fortissimo or very loud. As the waves move away from being sinusoidal, the harmonics become higher. This is because as we play louder, more pressure is being applied to the reed. The oscillations then change. Higher harmonics fall into the frequency sound range that is sensitive for humans, hence why high notes can be hard on one’s hearing. Flute vs. Clarinet • A clarinet is an closed structure, producing a wave length one-quarter the length of the instrument. The frequency is 140 Hz. All of the pressure is in the mouth piece and there is zero pressure in the bell (a pressure node) • A flute is an open structure, that produces a wave length one-half the length of itself. The frequency is 280 Hz. • The clarinet is one octave lower than the flute. Example- Flute vs. Clarinet • I took a look at an example from the site I grabbed this example off of. The formula for frequency is equal to speed divided by wavelength. • They give that a flute is .6 meters long and a clarinet is .6 meters also. Since a flute produces a wave half the length of itself, the wave would be 1.2m because two waves can go through. • A clarinet produces a wave one-fourth of the length, or four waves. The wave is 2.4m long. • So from this information and knowing that sound travels at 340m/s the frequency of a flute wave is equal to 340m/s/1.2m= 280 Hz and a clarinets wave frequency is 340m/s/2.4m= 140 Hz. • The longest wave of an instrument is it’s lowest note. A flutes lowest note is a C and with a clarinet it is a D# or a middle C. This proves that a clarinet is exactly one octave lower than a flute. Harmonics Harmonics are higher frequencies of played notes that occur from applying pressure onto the reed. You could also look at harmonics as different pitches. Because a clarinet is a closed tube instrument, it has mostly only odd harmonics unlike the flute. A full wave is the fundamental harmonic but after that the wave can be played in halves, quarters or thirds, etc. Sound Production • Sound is a wave that moves through the air because of variations of air pressure. • A clarinet produces sound through these basic steps: - The air in the instrument is of normal pressure and moves toward the bell (an opening). There is almost no pressure in the mouthpiece because of how closed it is. The reed is pulled closer into the mouthpiece. -The low pressure moves toward the bell and takes in the normal air pressure and changes direction and goes through the body of the clarinet. -The air is then evened out and the reed returns back to its initial position. The air from the player meets the moving air in the body and a high pressure wave escapes from the first open hole. Reed Types • As a clarinet player finding the correct hardness, shape and thickness of a reed depends on each player. Choosing the perfect reed makes all the difference in one’s pitch while playing. • Hardness is ranked 1-5, 1 being soft and 5 being hard. Generally, the harder reeds are better off for clarinetists who tend to bite down. There are also half step reeds, like 2.5, which are smaller steps in between hardness. • Many reeds change shape based on how the player bites down and plays. Sometimes, the player can shape the reed themselves. • There are wooden cane reeds and synthetic reeds. Synthetic reeds last longer than wooden ones, but tend to affect pitch and tone negatively. Wooden reeds are also adjustable to the players mouth. • Reed position is very important. When placing the reed on the mouthpiece you should leave a tip of space from where you place the reed to the top of the mouthpiece. I will discuss this further in the next couple of slides. The Four Rules of A Reed • My instructor always reminded us to keep our reeds properly placed and new. I never understood why but after doing some research I realized how a specific reed can effect pitch, tone and sound. • Response: a good reed should be able to perform at all dynamic levels such a p and ff. • Resistance: how hard you have to blow to produce little or lots of sound. A reed with low resistance is too easy and takes just as much work to play as a reed with high resistance. If a reed is either, a player can over blow, and the tone will not be perfect. • Tone Quality: is based on the hardness of a reed. If a reed is too soft, the tone will be dull. If a reed is too hard the sound can be shrill. • Stability: how the reed performs pitch (flat, stable, sharp, weak). I find this to be the most important. I feel this is what your audience will recognize if not perfect. If you cannot maintain a pitch, change your reed. Reed Positioning • Always make sure you start off with your reed center to the mouth piece. If the pitch and sound are not correct move it ever so slightly to the left or right. If those don’t work move the reed down from the tip of the mouthpiece. Also adjusting the ligature (the tightening piece) will create a stronger or lighter sound. This is controlling how much space a player has to press down on the reed with to create oscillations from the pressure. What I have Learned • Throughout this project I learned how I could better at playing my clarinet through how much pressure I apply and how my reed is. Before, whenever I had a problem with playing I would always have the conductor fix it for me. But now that I understand how the reed and clarinet work together, I can adjust on my own. • This project was related to the sound wave section we learned in class. Music is very interesting to me and I had a better understanding of it after physics. WORK CITED • Jones, Catherine S. "Harmonic Series." Connexions - Sharing Knowledge and Building Communities. Web. 22 Apr. 2011. <http://cnx.org/content/m11118/latest/>. • "Clarinet Acoustics: an Introduction." School of Physics at UNSW, Sydney, Australia. Web. 22 Apr. 2011. <http://www.phys.unsw.edu.au/jw/clarinetacoustics.html>. • "Clarinet." Wikipedia, the Free Encyclopedia. Web. 22 Apr. 2011. <http://en.wikipedia.org/wiki/Clarinet>. • "Open vs Closed Pipes (Flutes vs Clarinets)." School of Physics at UNSW, Sydney, Australia. Web. 22 Apr. 2011. <http://www.phys.unsw.edu.au/jw/flutes.v.clarinets.html>.