Continuing our series from classic horn text the next topic is the aperture or more properly aperture control, which is a key element for high range and tone development. It is a topic on which several wrote but in the case of this topic our focus will be on just one book and author that I believe is not read much at present but should be.
William C. Robinson in An Illustrated Advanced Method for French Horn Playing presented several ideas toward developing aperture control. He notes (the bolds are original to the quote) that
A different sized lip aperture is required for the production of each pitch at each different dynamic level, throughout the entire range. A high soft tone requires a smaller aperture than the same tone played at a louder volume. Lower tones require larger apertures than higher ones played at identical volumes. When the speed of the air remains constant, development of accurate control of pitch depends upon subtle and definite control of the lips immediately around the aperture, inside the mouthpiece.
Robinson in particular recommends bending of pitches (he calls the exercise “sustained tones with pitch variation”) to focus in on “the tone with the most desirable pitch and quality.” Also on a daily basis to develop aperture control he recommends long tones played with crescendos and diminuendos and harmonic series studies. Of the former he notes
As volume changes, pitch will also change, unless compensation is made by changing the size of the aperture. Control should be “set” in the corners of the lips and should always be maintained in all registers….
As to the harmonic series studies, a central concept of his pedagogy was the “minimum use of the embouchure.” It involved developing the relationship between air speed and the embouchure on any given note.
After adequate aperture control has been established, the next step is the development of air speed control. Using a minimum of aperture change and embouchure effort, concentrate on the use of various speeds of air. This will facilitate development of the subtle coordination between air and embouchure, with the air doing the greater amount of work and the embouchure doing as little as possible.
Exercises are presented which clarify his concepts of aperture control further. The higher notes are louder dynamics than the lower, with the highest the loudest and the lowest the softest. The instruction is to “Use the same sized aperture throughout (as nearly as possible), using varying air speeds to produce different pitches.”
Again, this is a classic book that contains a number of interesting concepts and exercises related to the aperture and aperture control in particular. It is available direct from the publisher Wind Music and according to the current price list online is a great bargain at only $8 a copy.
I also have a few more thoughts related to aperture control in this article, “Placing Pitch ‘in the Pocket.’”