At some point in your growth as a brass player, you’ll hear of a reference to “playing the slots” or “slotting your notes”. Of course, it will probably not be understood until you get some sort of explanation. So this article is my attempt at trying to clarify what this means and to do it in a way that you can understand it well enough to do a “search and discovery” in the practice room for practical use in performance.
Since we are always dealing directly with the physical universe with our bodies and instruments, it is necessary to start by stating in simple terminology what’s going on when we play. The science of physics ( of which I AM NOT an expert and certainly NOT a physicist ) is a vital area to focus on in getting started. In this field, there is a subject called fluid dynamics. This is simply a matter of air flow vs. resistance. When we take in air and then compress it, we are creating air pressure within the lungs. Then we must turn it around and force it out of the lungs, through the trachea ( throat ) and into and through the oral cavity ( mouth ), on into and thru the mouthpiece and finally through the horn. Our overall goal is to be able to control the velocity ( speed ) of the airstream. The greater the compression, the greater the velocity can be created. Anatomically, there are many muscles in action to produce this velocity. These muscles are part of what is referred to as thoracic muscles, or as we refer to our main torso as the thorax. More needs to be explained about these muscular functions but that’ll be in a different article on breathing and the respiratory system in general.
So, as the air moves upward and over the tongue surface and the palate ( roof of your mouth ), it will hit the inside of your top lip and push it forward towards the cup, allowing the air to go into the cup of the mouthpiece. As it enters the cup, some of the air will come back towards the lips in a “backdraft” action, simply stated. This causes the top lip to vibrate back and forth and while doing so, an eddy ( whirlpool ) will be forming around the inside of the top lip which activates a sympathetic vibration in the lower lip. So now both upper and lower lip surfaces are vibrating with an aperture ( opening ) between them to allow the air to flow on into the mouthpiece and then into and through the horn. It is the action of these lip vibrations that produces your sound. The instrument is more of an amplifier of those tones produced by the vibrations.
There is another thing that needs clearing up here and that is a semantics ( word definition ) issue. People often talk about lip buzzing and tell students to buzz their lips. This is defined as the lips squeezed much tighter together and producing a thin buzzing sound much like a bee or wasp. This is a great way to build muscle tone for the three primary muscles ( orbicularis oris, depressor, and buccinator ) that surround the embouchure area and that are essential in helping you develop as a player. BUT, when you are buzzing, there is almost no air flow that can allow you to perform. Buzzing is like doing situps to build strength but you must separate the lip surfaces and create an aperture in order to play. If your lips are touching when you try to play, you will have problems.
Okay, so perhaps over simplified, that’s how the machinery works for you to play. As the air moves into the horn, the mouthpiece and tubing “resist” the flow to varying degrees , depending upon their design factors. A larger, deeper cup and a larger bore horn will not resist as easily because there will be a degree of compression / velocity lost by the lack of resistance. I remember when I was early on learning to play, other players always spoke about horns having too much resistance, being “stuffy” so there was a tendency to gravitate to larger bore instruments thinking they would play more freely. And surprise, surprise when they merely found themselves working harder to play and losing some endurance as well. It turns out that resistance is your friend, not your enemy. But until you understand how it all works, you’ll be struggling with equipment choices as well as just about everything else that pertains to playing with ease and success.
So, what is a slot? Another very simple definition is a note that is BALANCED. That means machinery-wise, the balance between airflow and aperture size. These are all pertaining to two obvious aspects, DYNAMIC and REGISTER.
Regarding dynamic first of all, I often try to explain that rather than paying attention literally to the traditional dynamic markings of f’s , m’s, and p’s. These are merely visual and it is extremely difficult to precisely estimate the difference between p, pp, mp , etc. All they are referring to is SOFT. Then there is the f group. f, ff, fff all refer to LOUD. In MANY cases, this merely becomes OVERBLOWN and leaves the world of sound and enters the ugly world of NOISE!!! In between those, we have our friendly mf. That means MEDIUM.
So we can look at 5 different dynamics: TOO soft, soft, medium, loud, TOO loud!
By approaching things this way, it forces you to use your ear to fit in with what is going on around you and getting a better blend with the other players. You must learn to INTERPRET the page markings to understand the three workable and desirable dynamics of SOFT, MEDIUM, and LOUD and to avoid the two extremes of TOO!
The second aspect is register. This means low register, middle register, and high register. Ultimately, one can learn these elements of control well enough that you COULD look at your horn as having only one register from bottom to top. It IS POSSIBLE! So, a little bit of physics. The high register requires faster moving air and the opposite for the low register and then everything in between. Remember that we are striving to control our velocity. Faster moving air creates faster vibration in the lip surfaces which in turn produces higher pitched notes. It can be somewhat equated with a guitar string or a piano string except that our lips are one size whereas the strings on a piano vary in thickness and length, depending upon the register. What WE do is to vary the tension in the lip surfaces by using the muscle tone derived from having been on a very good program of lip buzzing as stated previously. And we vary the aperture size base upon the two items, dynamic and register.
So, when you play a note and it does not center well, doesn’t produce a full-bodied sound that FEELS centered and “locked–in” when it is played, you have no slot. EVERY note on your instrument is subject to the physical laws of overtones. These can be difficult to understand at first because you don’t initially hear them until they are missing. A note not centered will not have the ideal resonance that the overtones bring into the sound. These overtones add the “shimmer”, the “life”, the “prettiness”, the “clarity” to any note. Every note has various frequencies ( vibrating waves ) in it. There are higher ones, mid-range ones, and low ones. The lower register focuses more on the lower frequencies which move more slowly and then the opposite in the higher registers. Faster frequencies, brighter sound. We must learn to be aware of them when we practice and work on them consistently until they become second nature to us. By doing so, you gain a much higher degree of control over your sound quality and that also affects your other primary aspects of intonation, endurance, range….all things that add up to our BIG goal of EFFICIENCY. That is what the great players have mastered and to the degree that they have NOT, they might be able to play quite well by just determination and persistence but their endurance might suffer as well as their intonation, quality of sound, etc. So, following is a simple little drill that you need to start incorporating into your practicing. You’ll see that I believe strongly in starting in the middle register and working in both directions until your control extends to the concept of the “one register”.
Be warmed up but not tired. Take a fairly full breath. Play a G2 ( second line ) at an mf dynamic ( medium ). Gradually and slowly at first, drop your jaw with small increments of movement. You'll eventually experience two things …..More open sound and freer moving air. If you continue dropping the jaw, you'll reach a point of "too far" and the sound will start to shatter, get airy, and the pitch will drop. Plus, it will just FEEL wrong. Then raise the jaw back up until you get the two items back in place. So, somewhere in the "middle" you'll find your "sweet spot" where the two things are the best. That's called a “slot". It's where your airflow and aperture size become balanced acoustically ( physics ). This is where you'll get the maximum overtones in your sound, the richest resonance, the best center to the pitch of THAT NOTE AT THAT DYNAMIC. This is where it will SOUND GOOD and FEEL GOOD. This is a great definition that applies to gaining efficiency. It means getting the most product out with the least amount of effort, no extraneous pinching, pressing, grunting, squeezing, and mostly no PRAYING. I like to call them the three P’s ….. PINCH, PRESS, and PRAY!
So, repeat this several times until you gain good control of THAT NOTE at THAT DYNAMIC. Then increase the dynamic to loud and do the same thing repetitively to the same point of familiarity. Then do the same with soft dynamic to the same result. Learning to control ONE NOTE at all three dynamics is the beginning of learning to control ALL notes at all three dynamics. Simple, eh? Another good idea when you are initially learning this technique is to NOT avoid doing the TOO SOFT and the TOO LOUD. Your body will become very aware of the feelings you experience when playing these. Generally speaking, playing softly causes the average player to hold back in a state of fear and caution, being careful to not play too loudly. The action of holding back is a form of withdrawal and is NOT what you should be doing. Fear comes from not knowing. Knowing comes from experimenting until you DO know. If you avoid the mistakes in practice, you’ll never understand them well enough to solve the problems associated with playing that way. So, play the TOO SOFT and TOO LOUD until you recognize how bad they feel. AND THEN , omit them from your habits.
This exercise when done properly and musically becomes your lip or better stated, "jaw vibrato". Eventually you must start playing phrases utilizing the slot control device. Once you can really control this ONE note, second line G, move up the diatonic scale to A, repeating the process, and of course keep moving upward through this one scale to the first ledger line A above the staff. Then you should start moving downward to low C. Then perhaps starting on 2nd line G again, ascend to high B, and once centered go to high C. By this time you have the two octaves from low C to high C pretty well locked in. Now do this chromatically up and down to lock these other adjacent notes in as well. You’ll find that the majority of your playing and most of the beautiful music will fit in these two octaves. If you can play these well, you have a decent enough setup of mechanics to start extending your range above high C but keep everything gradual, half steps. If any note you go to does not center properly, DO NOT continue on but rather stop and handle the problem. I like to call this the “wipe your feet” rule. If you step in something that stinks, wipe your feet before continuing on because if you don’t , everything else you do will contain that stink. With a horn and embouchure, the stink is in the sound, the lack of slotting. Simple, eh? After these basics are established, you must start to open up the intervals but once again, be gradual. The wider the interval, the greater the challenge. There’s nothing to be gained by allowing your greatest enemy, your EGO, to try to run the show. Take your time and learn correctly.
I sincerely hope this article helps you understand how to start taking control of your playing by addressing the need to learn to slot and gain maximum efficiency in performance. Wishing you great success.