
Excerpts from Maestro Frisell's - 'A Singer's Notebook'
...It must be understood that all the tones of the singer's vocal range are, by nature, divided into two main groups, the Lower Register and the Upper Register. These registers possess inherent muscular differences which are also, in many ways, complimentary. One of the most important and generally overlooked aspects concerning the two vocal registers is that they are antagonistic towards each other. The antagonism remains in operation from the beginning phase of vocal training until the final phase of development. The accomplishment is generally known as the 'blending of the registers'. The muscle groups that produce the lower register's complete range of tones are inherently larger and more developed. Most training programs apply their basic exercises where the lower register is most powerful.
Singer and teachers working together are often volume conscious, impatiently seeking the quick attainment of 'resonant, powerful, professional sounding tones'. The generally fail to consider the developmental attributes of the upper register's muscular controls which are more subtle. These take longer to develop and take longer to reveal their true tonal qualities. The true worth of the first falsetto sounds, produced by the beginner are misleading, and rendering judgement should be reserved for expert ears.
Resolving the conflict between the two vocal registers can be accomplished, in part, by favoring the upper register. During early training the muscular activities of the lower register must be relegated to a temporarily passive and subordinate role. Many singers and teachers avoid a program of head voice and falsetto training because the falsettos sounds produced during the building process are unfamiliar, when compared to the sounds of the chest voice.