A low alto or contralto is supposed to go down to the E below; while altos of unusual range go high as
I even have seen the alto compass in notation run up to "high" C; but to control this high range an alto would have to be another Schumann-Heink who has cultivated upper notes in the head register. The tone-quality of some alto voices approaches so nearly that of the male voice, especially in the lowest tones of the chest register, that these altos are known as female baritones. In fact there is no voice in which register affects tone-quality as plainly as in alto. For in alto voices the chest register is apt to give tones that are heavy without corresponding vibrance and sonority, while tones produced in the adjustment of the head register are apt to be too thin. The middle register, however, produces in the alto voice a tone that is rich without being too heavy, so that it avoids undue heaviness on the one hand and on the other a thinness that is in no way comparable
with the light tones of soprano, but simply a thin and unsatisfactory alto. Alto tone in the middle register therefore gives the standard tone-quality for alto voice; and when singing in chest or head register, an alto should endeavor to relieve the chest notes of their heaviness and the head notes of their thinness by giving them as much as she can the quality of tones in the middle register. This can be accomplished by bringing head tones down to middle and by carrying the middle register adjustment down into the chest register. But all this is as much a matter of correct ear and trained will power to make the voice reproduce the mental audition as it is of physical adjustment.
The great prizes of the operatic stage and concert hall go to the higher voices—to sopranos, for example, instead of to altos. Yet the proper training of an alto voice is a most difficult matter because, while the chest register is the natural singing register of alto, it produces too "big" a tone—a tone so big as to be heavy and unwieldy. The middle register in alto really is an assumed position, yet it is the register in which the standard alto tone is produced. Teachers who either are ignorant of these facts or disregard
them are apt to carry up the cumbersome chest register until it meets the thin head register, producing a voice whose low notes are too heavy and tend toward the uncanny and by no means agreeable female baritone quality, while the higher notes are thin and undecided in character.
The male voice-range is the same as the female, save that it lies an octave lower; its mechanism is the same; and its registers are the result of identical physical functions. Thus, allowing for the octave difference, the tenor voice and the laws that govern it correspond for all practical purposes with soprano.