A transverse flute has a fixed tube diameter, and the length of the tube is changed by different fingerings (pitch).
There is an embouchure hole with an edge over which the lip plate must be positioned exactly and as parallel as possible by the flutist (“clean tone”).
The embouchure must be adapted in its shape and size to the respective tone, and the direction of the airflow must be adapted to the respective pitch (overblowing, timbres, dynamics, intonation).
The inside of the mouth can be changed; we can close or open the jaw more, move it forward or backward, and we can give this “mouthpiece” a different shape and diameter through the position of the tongue with different vowels (dynamics, intonation).
Through the mouthpiece and the embouchure, the air flows in a quantity and strength that we control through our respiratory muscles (support).
How is this now with our relatives, the recorders?
They also have a fixed tube diameter and change the pitch through fingerings. Opposite the labium is a fixed core slit in its size and shape, parallel and perfectly aligned. Overblowing works with a partial opening of the thumb hole (change in the vibration behavior in the tube). The mouthpiece is the part into which one blows, called the windway. Its diameter and shape are fixed by the instrument maker. So, the most flexible part remains the respiratory muscles and the possibilities to influence air pressure and speed inside the mouth.
Let’s look at the organ:
In common with the recorder, the organ pipe has a fixed size and alignment of the core slit. However, the organ has a special pipe diameter for each tone! This influences the air velocity. Each pipe has a “pipe foot,” which corresponds to the mouthpiece or windway and is built differently for each pipe. The organ has many registers and can thus produce different dynamics and timbres. Here, too, each tone has its own pipe. The organ has a rigid blower; the flexibility lies in the variety of pipes.
If we consider all this, the flute players have the most variables to operate. And they have to coordinate them optimally to produce a good performance. This is a great challenge, which also requires a long and in-depth engagement with the instrument.
Things become easier, however, when you better understand the connections. The garden hose can now help us with this: we get hoses in different diameters. If we send the same amount of water from the same tap through the different hoses with open ends, this water will have a different speed (analogy mouth interior: jaw position, vowels).
Then garden hoses have nozzles with which we determine how far and fast they should squirt: narrow nozzle = faster jet, opened nozzle = slower jet. (analogy lip plate) Then we have the tap: turned on more or less, a different amount and speed of water flows (analogy respiratory muscles).
And we can give the garden hose a direction, directing the water closer to us or further away from us with our hands (analogy: jaw position, lip movements/embouchure angle).
How should we combine the variables?
Some examples:
Low notes in forte require relatively a lot of, but slow air. Further jaw opening, darker vowel, e.g., “o,” wider and higher embouchure, lips direct the air steeply into the flute.
Middle-range notes require faster air, but not too much, otherwise, they will crack. If they do not get the fast air, they are often too low in mf and p. Move the jaw forward and upward, vowel “ü”, the embouchure is reduced by a movement of the lips, lips approach the edge and direct the air directly onto the edge. Or an example from the field of intonation:
A pp is played with a lot of air, but this must not be too fast, otherwise the tone becomes far too high, so the mouthpiece and the lip plate must be large and the embouchure angle steep. And conversely, the pp must not be too low. We need little, but very fast air, which means: slim tube, vowel “i,” small embouchure, flatter embouchure angle.
Dear flute players: All this shows us that our bodies must constantly map the many pipes of the organ in an elastic interplay because the flute is only one pipe! Therefore, André Jolivet says, in effect, that the flute is the most perfect of all instruments because it speaks directly from the soul to the human being!
You can find more information in my booklet “fit for the flute – Klang und Intonation” (UE 31292).
Good luck!
This article appeared in the magazine “Bayrische Blasmusik”, issue 11/214.
To pronounce the vowel “ü”, try the english “ee”, like eery, but with rounded lips.