For any given fingering, reed and mouthpiece set-up, the player can make a range of sounds, varying the pitch, loudness and spectrum. Various control parameters are available to the player: pressure in the mouth can be varied, so can the bite force, the position at which the lip presses on the reed, the damping of the lip and sometimes the configuration of the vocal tract. To investigate this, we used the 'robot player' to vary these parameters in a controlled way.
We report these results in more detail on the clarinet robot site, along with links to a scientific report on that project. The tongue can completely or partially interrupt the air flow by displacing and releasing the reed, which is how most notes are started. During the attack, the reed is inputting more energy than the bore is losing, so the sound grows, and conversely at the end of the note.
There are quite a lot of effects to discuss here, so we have a separate page for that. The behaviour of closed and open pipes are explained in Open vs closed pipes Flutes vs clarinets , which gives more explanation of this animation.
For the purposes of this simple introduction to clarinet acoustics, we shall now make some serious approximations. First, we shall pretend that it is a simple cylindrical pipe — in other words we shall assume that all holes are closed down to a certain point, at least , that the bore is cylindrical, and that the mouthpiece end is completely closed.
This is a crude approximation, but it preserves much of the essential physics, and it is easier to discuss. We look at many of the complications in turn below and when explaining the real results. The natural vibrations of the air in the clarinet, the ones that cause it to play notes, are due to standing waves. If you need an introduction to this important concept, see standing waves. What are the standing waves that are possible in such a tube? The fact that the clarinet is open to the air at the far end means that the total pressure at that end of the pipe must be approximately atmospheric pressure.
In other words, the acoustic pressure the variation in pressure due to sound waves is near zero. The mouthpiece end, on the other hand, can have a maximum variation in pressure. Now the distance between a zero and a maximum on a sine wave is one quarter of a wavelength. So, the longest standing wave that can satisfy these conditions is one that has a wavelength four times the length of the instrument, as shown at the top of the next figure: it has zero pressure at the open end called a pressure node.
Inside the tube, the pressure need not be atmospheric, and indeed the maximum variation in pressure the pressure anti-node occurs in the mouthpiece. The standing wave is sketched below.
The bold line is the variation in pressure, and the fine line represents the displacement or the amplitude of the vibration of the air molecules. The displacement curve has an anti-node at the bell: air molecules are free to move in and out at the bell but, in the approximation where the mouthpiece is closed, there is little acoustic flow in the mouthpiece.
There is of course DC flow, but that does not affect the standing waves directly. The frequency equals the wave speed divided by the wavelength, so this longest wave corresponds to the lowest note on the instrument: D3 on a Bb clarinet.
See standard note names , and remember that clarinets are transposing instruments, so that D3 is written as E3 for the Bb clarinet. Hereafter we refer only to the written pitch. Then check the answer in the note table. You will find that the answer is only approximate, because of end corrections. You can play written E3 with this fingering, but you can also play other notes by overblowing — by changing your embouchure and changing the blowing pressure.
These other notes correspond to the shorter wavelength standing waves that are possible, subject to the condition that the sound pressure be zero at the bell and a maximum in the mouthpiece. The first three of these solid lines are shown in the diagram below.
These three notes are approximately members of the harmonic series. Notes with these frequencies have the written pitches shown below. The complete harmonic series has the frequencies f o , 2f o , 3f o , 4f o , 5f o etc. The clarinet, under these conditions, plays approximately the odd members of the series only. The missing even harmonics and their waves are shown in dashed lines and in parentheses in the diagrams.
You might like to compare this with the analogous diagram for the flute , which has all harmonics present. There is also a more detailed discussion of the harmonic series of open and closed pipes. Harmonics of the lowest note on a clarinet. Recording of notes played using only the fingering for the lowest note. The notes in the diagram are the harmonics of the fundamental. The notes in the sound file are those played by overblowing, without using register keys which is one reason why they don't sound pretty and don't start cleanly.
You will observe that the played notes are successively flatter than the harmonic frequencies. The third is slightly flatter than B4, the fifth is about a semitone flat, the seventh more flat again.
This is due to effects of the reed itself a deformable element approximately in parallel with the bore and effects of the bell longer wavelengths penetrate less into the bell before being reflected. When the clarinet is playing, the reed is vibrating at one particular frequency. But, especially if the vibration is large, as it is when playing loudly, it generates harmonics see What is a sound spectrum?
The reed vibration tends to have both odd and even harmonics. However, in the low registers at least, only the odd harmonics set up, and are in turn reinforced by, standing waves. Consequently, the sound spectrum in the low register has strong first and third harmonics, but weak second and fourth. This is not true of the clarino register and above. Observe that this note, which uses only a little more than half of the length of the clarinet, is still lower than the lowest note on a flute.
This is one of the big advantages of a closed pipe: you get low notes with a shorter pipe. For the moment, we can say the an open tone hole is almost like a 'short circuit' to the outside air, so the first open tone hole acts approximately as though the clarinet were 'sawn off' near the location of the tone hole.
This approximation is crude, and in practice the wave extends somewhat beyond the first open tone hole: an end effect. For the technically minded, we could continue the electrical analogy by saying that the air in the open tone hole has inertia and is therefore actually more like a low value inductance.
The impedance of an inductor in electricity, or an inertance in acoustics, is proportional to frequency. So the tone hole behaves more like a short circuit at low frequencies than at high. This leads to the possibility of cross fingering , which we have studied in more detail in classical and baroque flutes. The frequency dependence of this end effect means that the low note played with a particular fingering has a smaller end effect than does the corresponding note in the next register.
If the clarinet really were a perfect cylinder with tone holes, then the registers would be out of tune: the intervals would be too narrow. This effect is removed by variations or perturbations of the cylindrical shape, including the shape of the mouthpiece, an enlarging of the upper region of the bore, and a gradual flare in the bottom half of the instrument, leading to the bell.
Holes can also serve as register holes. For instance, if you play Bb3 call this frequency f o and then open the register key or speaker key , you are opening a hole one third of the way down the closed part of the instrument.
See the middle diagram below. This hole disrupts the fundamental, but has little effect on the higher harmonics, so the clarinet 'jumps up' to F5 3f o.
Where to put it? The acoustically obvious place to put a register hole is at a pressure node of the upper note which is also a region of large pressure variation for the lower note. Opening the bore to atmospheric pressure at a pressure node makes no difference to that note.
The trouble is that each note in the upper register has its pressure node at a different position. One can imagine a clarinet that had a separate register hole for each note, but that would be a lot of keys. In fact, only one register hole is used for the second register from B4 to C6. Looking at the diagram below, we see that it its position is a compromise: for B4 it is well below the pressure node, and for C6 well above. This is not a big problem in practice. The register hole is small, so it is not really a 'short circuit', except at low frequencies.
We explain how the mass of the air seals the hole at high frequencies below. So it does not too much affect the third and higher harmonics. It does however disrupt and detune the fundamental, and that is its purpose: to stop the instrument dropping down to its bottom register.
We mention in passing that the saxophone has two dedicated register holes for the second register and an automated mechanism that allows only one key to operate the hole appropriate to each end of the range. Multiple register keys have been tried on the clarinet, but have never become popular.
The speaker key is the register key used for the second register. In higher registers, other register holes are used: the altissimo register uses the hole that is normally closed by the index finger of the left hand.
This hole is designed primarily as a tone hole, so it is bigger than it need or should be for an ideal register hole. This defect is not so important because it is used only for high frequencies, where its inertance is large. However some players partly cover this hole half-holing when using it as a register hole. When we play E3, the reed vibrates at the frequency of E3 about Hz for a Bb clarinet. In a steady vibration, only harmonics odd or even of this frequency are possible, and they are exactly harmonic.
See How harmonic are harmonics? The odd harmonics are supported by the resonances of the bore, and so the resultant sound spectrum is rich in odd harmonics but has weaker even harmonics, at least at low frequencies.
See How the reed and pipe work together. When we play B4 , the reed vibrates at the frequency for this note about Hz for a Bb clarinet , which is three times the frequency of E3.
Again, in steady vibration only harmonics odd or even of this frequency are possible. The fifth resonance of E3 approximately G 5 is still present, as the impedance spectrum for B4 shows, but there is nothing to put energy into a vibration at that frequency. Observe also that we are now in the clarino register about which see the general comments on the page for B4.
The resonances that one might have expected to support the 3rd and 5th harmonics of B4 — i. However, the acoustic response of the clarinet is strong enough to help all of the harmonics of the reed to some extent, and the resultant sound spectrum has no strong differences between even and odd harmonics.
We return to discuss register holes in more detail below , after we have discused the frequency response. An open tone hole connects the bore to the air outside, whose acoustic pressure is approximately zero.
But the connection is not a 'short circuit': the air in and near the tone hole has mass and requires a force to be moved. So the pressure inside the bore under a tone hole is not at zero acoustic pressure, and so the standing wave in the instrument extends a little way past the first open tone hole.
There's more about this effect under Cut-off frequencies. Closing a downstream hole extends the standing wave even further and so increases the effective length of the instrument for that fingering, which makes the resonant frequencies lower and the pitch flatter.
The effect of cross fingerings is frequency dependent. The extent of the standing wave beyond an open hole increases with the frequency, especially for small holes, because it takes more force to move the air in the tone hole at high frequencies. This has the effect of making the effective length of the bore increase with increasing frequency. As a result, the resonances at higher frequencies tend to become flatter than strict harmonic ratios.
Because of this, often one cannot use the same cross fingerings in two different registers. Because the clarinet's tone holes are relatively large, cross fingering makes only modest changes to pitches in the chalumeau and clarino registers, but they can sometimes be useful in adjusting the pitch.
A further effect of the disturbed harmonic ratios of the maxima in impedance is that the harmonics that sound when a low note is played will not 'receive much help' from resonances in the instrument. Technically, the bore does not provide feedback for the reed at that frequency, and nor does it provide impedance matching, so less of the high harmonics are present in the reed motion and they are also less efficiently radiated as sound.
See Frequency response and acoustic impedance. To be technical, there is also less of the mode locking that occurs due to the non-linear vibration of the reed.
As a result, cross fingerings in general are less loud and have darker or more mellow timbre than do the notes on either side. You will also see that the impedance spectrum is more complicated for cross fingerings than for simple fingerings, especially in the region around 1. We have studied cross fingerings more extensively on flutes than on clarinets, by comparing baroque, classical and modern instruments.
We have not yet studied a chalumeau or classical clarinet to compare with the modern instrument. See cross fingering on flutes or download a scientific paper about crossfingering. So high frequency waves are impeded by the air in the tone hole: it doesn't 'look so open' to them as it does to the waves of low frequency. That would be pretty cool to see.
What's the difference between a student grade clarinet, an intermediate grade clarinet, and a pro grade clarinet assuming that the player is skilled enough to play each horn exactly like the other horns?
You will see more of the even partials with the pro grade horn. They will be subtle, but they should be there. The lower grade horns will have progressively less of the even overtones as the overall quality of the horn goes down.
Well, at least that's the theory, anyway. What do you think? Author: Dee Date: paul wrote: Author: Don Berger Date: I believe we should clear up a bit of confusion re: harmonics vs overtones. Likely the best reference is Benade's fine p-back book, "Horns, Strings, and Harmony" which leads the reader gently into the deep water of musical physics, see pgs on harmonics. Others, please consider and correct me if needed. Author: paul Date: Pardon me for using the word "theory" rather loosely in my posting above.
The "richness" or quality of the tone on a pro grade horn is due to many hardware based factors. Undercut tone holes, a polycylinidrical bore, highly tweaked placement of keypads, a superbly crafted mouthpiece, a highly customized reed, etc. Even then, you may find disagreement on the impact that each of these items has on the quality of tone that a particular horn can produce. My real point was that all of this may look good on paper and may have validity somewhere, but I have to believe that the skill of the player has a huge significance when it comes to the quality of the tone.
Pure hardware based and totally unbiased theory versus actual reality can be radically different when you introduce people with all kinds of skill levels into a situation like this. For instance, there have been many references in this BBS about professional performers who could make any horn of any grade sound great and there are many examples of novices who could make a top-of-the-line pro grade horn sound absolutely terrible.
That's what I meant when I used the word "theory". Practice, practice, practice Author: Clarinetgirl06 Date: So I am confused. I can hear an overtone of an octave above on my clarinet, especially on certain notes. I was under the impression that this isn't ordinary for a clarinet because it only has odd partials or something. So is this overtone of an octave on a clarinet normal or not?
If it's not normal, what's wrong? Author: clarnibass Date: Carrie, pretty much all instruments as far as I know have all the overtones. It is just how loud they are, and on the clarinet the octave is so weak, it is very unlikely you are hearing it. Is it possible that you are imagining it? Author: L. We would of course do not recognize a particular note if the designated frequency was not the predominant in terms of sound amplitude and even harmonic series frequency of the sound produced although the human brain does processing of a multitude of frequencies to a more simple sound perception.
Pure frequency progressions 2. The depth and character two subjective terms of a note produced on the clarinet is determined by the number of frequencies, series in the odd ranking of 1,3,5,7,9 etc. The brain processes the frequency series presented and makes its own valuation on the sound quality which has been patterned by our evolution - most suggest - from sounds common in the natural environment.
Certain sounds - e. The tone hole placement on the tube, the depth of the tone hole from the bore, the shape which includes undercutting , the height of the pad and material of the pad above the tone hole which attenuates the escaping air column, and the characteristics of the fluctuating air column itself in the tube all interact to form the note produced.
The player, mouthpiece, reed, ligature, and barrel are responsible for producing the fluctuating air column entering the instrument which is then modified by the size and shape of the bore of the instrument.
Actually, the former is a simplistic explanation because the total air column within the instrument which is a combination of all factors which allow the fluctuating air column to escape through any given hole or series of open holes is modulated by the actions of the barrel up components most important of which is the player. Some would say the material of the tube and the associated keywork hung on the tube, not me, adds another dimension to the frequencies produced.
Since you can only put so many holes in the tube with a mechanism to open and close off the holes there are trade offs in tone hole placement to produce all the notes produced on the clarinet.
Different manufacturers have devised common but still individual solutions to these trade offs of tone hole placement and this is largely responsible for particular and characteristic sound signature particular groupings of frequency series of different instruments. Analysis of the frequency patterns produced by the clarinet is very complex because application of subjective although objective as interpreted by the brain attributes - e.
With the help of some talented mathematicians we have been able to sort out some proprietary algorithms which favorably compare with subjective opinions of sound quality by the majority of a test panel of expert players. We have also been able to correctly identify and separate by sound signature the major brands of instruments.
With these tools it may be possible to access changes in hardware from the barrel up to their corresponding subjective effects. The player of course influences all of these factors by their interaction with the hardware so the change and effect is player specific - however with a large number of players some general effects may be evident. At the ends of an organ pipe open at both ends, what do we always get-nodes or antinodes?
Which harmonics are present in the note produced from a pipe closed at one end? The harmonics formed in air column in an organ pipe closed at one end are.
The length of pipe closed at one end and open at both ends is 32 cm each. The frequency of first ove An organ pipe of length L open at both ends is found to vibrate in its harmonic when sounded with a Are these Answers Helpful? Yes No. Disclaimer The questions posted on the site are solely user generated, Doubtnut has no ownership or control over the nature and content of those questions.
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