When _oo_, _a_, and _e_ are auxiliary vowels, they need not be plainly pronounced. (They form an exception in the diphthongs, "Trauuum," "Leiiid," "Lauuune," "Feuyer," etc.) As auxiliary vowels they are only means to an end, a bridge, a connection from one thing to another. They can be taken anywhere with any other sound; and thence it may be seen how elastic the organs can be when they are skilfully managed.
The chief object of the great scale is to secure the pliant, sustained use of the breath, precision in the preparation of the propagation form, the proper mixture of the vowels which aid in placing the organs in the right position for the tone, to be changed for every different tone, although imperceptibly; further, the intelligent use of the resonance of the palate and head cavities, especially the latter, whose tones, soaring above everything else, form the connection with the nasal quality for the whole scale.
The scale must be practised without too strenuous exertion, but not without power, gradually extending over the entire compass of the voice; and that is, if it is to be perfect, over a compass of two octaves. These two octaves will have been covered, when, advancing the starting-point by semitones, the scale has been carried up through an entire octave. So much every voice can finally accomplish, even if the high notes must be very feeble.
The great scale, properly elaborated in practice, accomplishes wonders: it equalizes the voice, makes it flexible and noble, gives strength to all weak places, operates to repair all faults and breaks that exist, and controls the voice to the very heart. Nothing escapes it.
By it ability as well as inability is brought to light--something that is extremely unpleasant to those without ability. In my opinion it is the ideal exercise, but the most difficult one I know. By devoting forty minutes to it every day, a consciousness of certainty and strength will be gained that ten hours a day of any other exercise cannot give.
This should be the chief test in all conservatories. If I were at the head of one, the pupils should be allowed for the first three years to sing at the examinations only _difficult_ exercises, like this great scale, before they should be allowed to think of singing a song or an aria, which I regard only as cloaks for incompetency.