The Harmonic Series
What makes brass unique from every other instrument family?
When it comes to strings, woodwinds, and keyboard instruments, you can actually see the position of each note, and how the notes relate to each other. With brass instruments on the other hand, there’s a series of notes that you cannot see, called the harmonic series, and to play any brass instrument, one must learn how to navigate it.
It follows a somewhat consistent pattern, forming intervals that are deeply embedded in the human ear, comprising the building blocks of nearly all music heard across the globe. Playing a natural trumpet (or horn) is perhaps the most direct way of experiencing the harmonic series - it puts one in touch with the physical nature of sound itself.
If you cannot see the notes, how can you play them?
That's the mystery! There are no holes to cover (or uncover), keys to push, finger positions to adjust, and with a natural trumpet, no valves to push or slide to move. Technically speaking, in order to sound an individual note of the harmonic series, the player must produce a lip-vibrated frequency that matches a resonance frequency of the instrument's air column. Put more simply, producing a precise frequency of lip-vibration is very similar to singing a sustained pitch. In the case of playing brass, the breath, mouth, tongue, lips, and an internal sense of pitch are required to sustain and manipulate sound, and shifting between the notes of the harmonic series is perhaps the most challenging aspect of learning any brass instrument.
In the BfB curriculum, these notes are referred to as harmonic notes*, and because all notes in the lower - middle register of the harmonic series form consonant intervals, students can experience success right away without having to worry about playing a "wrong note." This gives them an opportunity to gain confidence in sound production while they develop the more precise skill necessary to play specific harmonic notes.
So, how does one move between the notes of the harmonic series?
There are several variables that come into play when shifting between notes of the harmonic series, including embouchure formation, tongue position, air speed, aperture size, and mouthpiece pressure, to name a few. The BfB teaching method presents and discusses these variables, but it maintains a primary focus on vocalization to tap into student's inherent musical abilities as they develop this basic technique.
How does the BfB method teach students about the harmonic series?
In "Chapter 3: Stumbling on H2," our imaginary prehistoric trumpeter Ragnar accidentally discovers that a stick trumpet he has made can play two notes (although they sound far from "harmonic"). The story shows how he then used these two notes to make songlike music. To learn how to move up or down between these notes, students go to the Practice Cave, either led by their teacher in the classroom, or at home using the internet. They listen, sing along, and play along, until they are able to match the notes in the exercises and pieces. Pedagogically speaking, as students "stumble on" more harmonic notes, it becomes increasingly important for them to vocalize before playing in order to establish a close relationship between their voice and lip-vibration. Singing with solfegio helps students develop awareness of how the resulting intervals align with the diatonic system. Singing with vowels helps coordinate tongue position with pitch change. But it is experiencing the actual pitch vibration with the voice (in the body) that can have the greatest impact on development. Several teaching strategies relating to these issues are laid out in the online teacher’s edition along with suggested learning activities.
Students who have a chance to develop this basic skill on a natural trumpet gain a deep understanding and life-long appreciation of brass, and those who continue on to play modern brass instruments hit the ground running.
*The term “harmonic note” is technically a misnomer, because the word “harmonic” implies a relationship between two or more resonance frequencies of the harmonic series. A “note” therefore cannot be “harmonic.” In the Cambridge Encyclopedia of Brass Instruments, these notes are referred to as the “natural notes,” as in the “naturally occurring notes” of a lip-blown instrument — not to be confused with “natural,” as in neither flatted (♭) nor sharped (♯).