Range and register.
The range of choral voices is slightly more limited than that of soloists. The exceptional register may be considered as two notes above and below the normal octave. The dotted lines extended still further indicate the limits upon which a composer may rely in very exceptional cases, as every full chorus must contain a few voices of more than average compass, in this respect approaching the solo voice in character. In many choruses one or two bass singers may be found who are able to go still lower than the limit of the exceptional range (they are called octavists).[19]
Note. These uncommonly deep notes must be moderately well sustained and can only be used when the whole chorus is singing quite piano; they are hardly applicable except in unaccompanied choruses (a cappella).
The difference in range between the "firsts" and "seconds" in each type may be fixed as follows: the normal octave and the exceptionally low register should be allotted to the "seconds", the same octave and the exceptionally high register to the "firsts".
The composition of the chorus is approximately as follows: for a full chorus, 32 singers to each of the 4 parts sopr., alt., ten. and bass; for a chorus of medium size, from 16 to 20, and for a small chorus from 8 to 10 singers. The number of women will often predominate, and more voices are given to the "firsts" than to the "seconds".
On account of stage requirements a chorus may have to be divided into two or even three separate parts. This is a great disadvantage, especially with a small chorus, as each chorister becomes more or less a soloist.
The methods of writing for operatic chorus are very numerous. Besides the primary harmonico-polyphonic arrangement, containing the whole musical idea, the voices may be made to enter separately, singing or declaiming phrases of varying length; they may progress in unison or in octaves; one vocal part may repeat certain notes or the whole chorus reiterate certain chords; one melodic part may predominate (the upper part for preference), the others forming an harmonic accompaniment; isolated exclamatory phrases may be given to the whole chorus or to certain portions of it, and finally, the entire chorus may be treated in a purely harmonic manner in chords, with the essential melodic design allotted to the orchestra. Having outlined the principal methods of handling the chorus, I advise the reader to study vocal and orchestral scores where he will find many illustrations impossible to deal with here.
There exists another most important operation, the division of the chorus into different groups. The most natural method is to divide it into men's chorus and women's chorus. Less frequent combinations are altos, tenors and basses, or sopranos, altos and tenors. There remains yet another point to be considered, the sub-division of each part into two's and three's. Men's and women's choruses, considered as distinct unities may alternate either one with the other, or with the principal chorus. For this reason sub-division increases the possibilities of choral writing, and, as I have already remarked, it is only by the study of choral works that the student will acquire mastery over this branch of composition, the fundamental principles of which can only be faintly outlined in the course of the present work.