against the
palate and drawn up behind (see plate _a_), the furrow is formed of
itself. In pronouncing the vowel _ah_ (which must always be mixed with
_[=oo]_ and _o_), it is a good idea to think of yawning.

The furrow must be formed in order to allow the breath to resonate
against the palate beneath the nose, especially in the middle range;
that is, what a bass and a baritone (whose highest range is not now
under consideration) would call their high range, all other voices
their middle.

Without the furrow in the tongue, no tone is perfect in its resonance,
none can make full use of it. The only exception is the very highest
head and falsetto tones, which are without any palatal resonance and
have their place solely in the head cavities. Strong and yet delicate,
it must be able to fit any letter of the alphabet; that is, help form
its sound. It must be of the greatest sensitiveness in adapting itself
to every tonal vibration, it must assist every change of tone and
letter as quick as a flash and with unerring accuracy; without
changing its position too soon or remaining too long in it, in the
highest range it must be able almost to speak out in the air.

With all its strength and firmness this furrow must be of the utmost
sensitiveness toward the breath, which, as I have often said, must not
be subjected to the least pressure above the larynx or in the larynx
itself. Pressure must be limited to the abdominal and chest muscles;
and this might better be called stress than pressure.

Without hindrance the column of breath, at its upper end like
diverging rays of light, must fill and expand all the mucous membranes
with its vibrations equally, diffuse itself through the resonance
chambers and penetrate the cavities of the head.

When the back of the tongue can rise no higher, the larynx must be
lowered. This often happens in the highest ranges, and one needs only
to mingle an _oo_ in the vowel to be sung, which must, however, be
sounded not forward in the mouth but _behind the nose_. When the
larynx must stand very low, the tongue naturally must not be _too_
high, else it would affect the position of the larynx. The mass of the
tongue must then be disposed of elsewhere; that is, by the formation
of a furrow (see plate). One must learn to feel and hear it. To keep
the larynx, the back of the tongue, and the palate always in
readiness to offer mutual assistance, must become a habit. I feel the
interplay of tongue and