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Overtone Series/ Position Chart for Trombone

 

An understanding of the natural science behind the trombone will assist you greatly in your studies. Without getting terribly technical, allow me to explain the physical properties behind the trombone in particular and brass instruments in general.

First off, the trombone is a tube. A metal tube into which a vibrating column of air is sent to produce a sound. The air column is provided by your lungs and is put into vibration by your lips. If given any set length of tube and asked to "buzz" the lips into it, you would be able to attain certain pitches. The timbre (tonal quality) and resonance of these pitches would depend quite a bit on the material from which the tube was made and the shape of any "mouthpiece" you might use.

Over many,many years, brass became the material of choice because of it's beautiful resonant qualities and it's ability to be "worked with" by instrument makers. Original "brass" instruments were not always made of brass, though. Animal horns, wood, bone, shells, and a variety of other metals were and still are experimented with by "brass" instrument makers.

Nevertheless, any length of tube will give a certain assortment of pitches and these pitches will follow a very specific pattern. This pattern is known as the natural Overtone Series.

(by the way.....if this stuff interests you, read Paul Hindemith's Craft of Composition. It has a very interesting, yet complex, explanation of the natural Overtone Series. He knew what he was doing!)

If this stuff is confusing to you, email me and I'll try to make it more clear.

Each pitch in the series is called a "partial"......never mind why. It's probably because it is a partial frequency of the entire series.

The lowest pitch you can attain is known as the Fundamental pitch. A trombone is said to be "in Bb" because it's fundamental when in first position is a Bb. Similarly, a trumpet "in C" has a fundamental pitch of C when no valves are pressed. Pressing valves on a trumpet adds length to the tube, just as our slide does on the trombone.

Every pitch above the Fundamental is technically referred to as an "Overtone".......as in "OVER the fundamental".

The terms partial and overtone, then, are not the same. Sadly, many folks use these terms interchangeably and this leads to a great deal of confusion.

The first PARTIAL is the FUNDAMENTAL pitch.

The first OVERTONE would technically be the SECOND partial, or the first pitch "OVER" the fundamental.

As far as pitch is concerned, there are a few tendencies in the Overtone Series. The natural series, you would think, should sound fine to our very natural ears. But it doesn't.............

For a variety of reasons, not least of which is the Tempered tuning scale made popular by keyboards, the natural series sounds anything but natural to us. SO.........we must make adjustments to please our ears and play "in tune" with other musicians (ESPECIALLY keyboardists, who can do very little to change their pitch:-)

These adjustments will be done with the slide and will vary from trombone to trombone, but IN GENERAL, remember this:

1) In any given position, the Overtone Series is an extension of the fundamental pitch. That would be a Bb series in first position, an A series in second, Ab in third, etc. Before valves were invented, by the way, the only thing a player could do to achieve a different overtone series was put in a different "crook" to change the length of his/her instrument. Without doing this, they were stuck with the few pitches they could achieve in the Overtone series that corresponded to the length of their tube. (Come to think of it, I'll bet gigs were pretty easy when you only had to play 4 or 5 notes!) The moving slide was really a stroke of genius! Valves didn't come till much later, and they're STILL being improved upon.

2) Partials 1,2,4, and 8 in any Overtone series will be the same pitch name, just in different octaves. All Bb's in first position, A's in second, etc. What this means is that no adjustment on the slide should be made for these partials.........and this is most often true on a good instrument.

3) The 5th partial on many trombones is often SHARP in first position, then a little less sharp in 2nd position and flatter and flatter as you go out to 7th position. ARGH!

3) The 6th partial is usually sharp on most trombones. Get with a tuner and see if this isn't the case with yours. If a pitch is sharp, we must lengthen the tube to lower the pitch. The longer the position, the more you'll have to move the slide to make these adjustments. So, that means that if you need to move the 6th partial F in first position 1/8 of an inch, you may have to move the Eb 6th partial in third position 1/4 of an inch. Again, this will vary among instruments and a tuner will be your best friend in finding the tendencies on YOUR trombone!

4) The 7th partial (Ab in first position) will be very flat in each position. QUESTION: Why do we never play Ab in first position? ANSWER: We can't make the tube any shorter to adjust for intonation! AND......If we are playing the G above the staff in 2nd position, we better pull the slide in! Gb in 3rd, F in 4th.....same thing.

5) The 9th partial is uaually sharp and the 10th very often flat.

Sit Down With A Tuner and Find the Pitches on Your Trombone!

If you need help..........email Tom:

Here's a Position Chart Outlining the Overtone Series in each position on the Trombone

* IMPORTANT: The 11th Partial is not shown in any of these overtone series because we very rarely use it. There is a gap between the 10th and 12th partials in my chart. The first pitch you see in each series is the fundamental. We also call these "pedal notes" on the trombone because these pitches are achieved with the foot pedals on an organ.

 

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