Trumpet Transposition Formula by Eddie Lewis
Transposition can be confusing and sometimes frustrating. In our early years of learning to transpose, we learn the B flat transposition, then F and E flat. Unfortunately, those standard transpositions do not cover all of the possibilities.
What do you do if you are playing a piece in the key of G, written for A trumpet, but you are playing on an E flat instrument? It’s confusing. That’s not a transposition you will learn in your college trumpet lessons.
That’s why I created a formula that avoids learning those different transpositions separately. In my mind, there is no C transposition or F transposition, etc. There is only a general system of transpositions that put you on the right notes, regardless of what horn you are playing on or what instrument the part was written for.
From You to the Page
The first step in this formula is to determine the interval of the transposition. Just think “From and to.” What is the pitch of the instrument I am playing? What pitch instrument was the part written for? Going from you to the written part, what is that interval.
It’s very important that you get the direction of the interval correct. From you to the page! If you are playing a B flat trumpet, reading a D trumpet part, the interval is up a major third. From B flat to D is up a major third. If you are playing a piccolo trumpet with an A slide, reading a part written for E flat trumpet, the interval is down a tritone. It is a descending interval because the piccolo trumpet is higher than the E flat trumpet.
Transpose the Key Signature
After you have determined the interval of the transposition, the next step is to transpose the key signature. Apply the transposition interval to the key. If the music is in the key of C, and the transposition interval is down a tritone, then transpose the key signature to F sharp or G flat in your mind. If the key of the music is D, and your transposition interval is up a fourth, then transpose the key signature to G in your head.
By transposing the key before you begin transposing the notes, you allow your mind to tap into all of the scale work you have done. Scale exercises help us to think in the key of that scale. Exercises in F sharp help us to think in F sharp. When we transpose the key signature before we transpose the notes, it makes our job easier by relying more on our previous practice efforts and less on our ability to think in the moment. This is one of the most important reasons why we practice scales, to make transposition, sight reading and improvisation more automatic.
Transpose Groups of Notes
One of the best advantages to transposing this way is that you no longer have to concern yourself with the quality of the interval. When you transpose the key signature in your mind, you can simplify your thoughts to only the interval.
If the transposition interval is up a minor third, from the key of D, then to the key of F will insure that all of the notes transposed will be a minor third apart.
The exception, of course, is when there are accidentals. When you encounter an accidental, you must apply that alteration to the key you have changed to in your mind. If there is a written G sharp in the key of D, then you must raise the B to a natural in the key of F when you transpose.
At first, the accidentals can be tricky. Just keep working on it. You will get better as you spend more time practicing your transposition.
As your ability to transpose grows, you will begin to thinking in two keys at once. You will be able to think in the written key while simultaneously thinking in the key you are playing in.
The Importance of Scales
If you have practiced your scales correctly, you should be able to transpose groups of notes instead of bogging down and thinking about each of the notes individually. The reason why we practice comprehensive scale patterns is because those scale patterns are the building blocks of music. We practice three notes sequences, four note sequences, thirds, fourths, and diatonic triads so that the technique is automatic when we encounter those elements in the music.
Transposition Formula Summary
Determine the interval by asking yourself, what is the interval FROM the key of the instrument I’m holding in my hands TO the key of the instrument the music was written for?
Transpose the key signature according to that interval.
Transpose groups of notes based on their position within the key.
Keep an eye out for traps such as large intervals and accidentals.
Eddie Lewis is a Houston, Texas area professional trumpeter and music educator.