Part V. The Singers
12. With the exception of the melodies proper to the celebrant at the altar and to the ministers, which must be always sung in Gregorian Chant, and without accompaniment of the organ, all the rest of the liturgical chant belongs to the choir of levites, and, therefore, singers in the church, even when they are laymen, are really taking the place of the ecclesiastical choir. Hence the music rendered by them must, at least for the greater part, retain the character of choral music.
By this it is not to be understood that solos are entirely excluded. But solo singing should never predominate to such an extent as to have the greater part of the liturgical chant executed in that manner; the solo phrase should have the character or hint of a melodic projection (spunto), and be strictly bound up with the rest of the choral composition.
13. On the same principle it follows that singers in church have a real liturgical office, and that therefore women, being incapable of exercising such office, cannot be admitted to form part of the choir. Whenever, then, it is desired to employ the acute voices of sopranos and contraltos, these parts must be taken by boys, according to the most ancient usage of the Church.
14. Finally, only men of known piety and probity of life are to be admitted to form part of the choir of a church, and these men should by their modest and devout bearing during the liturgical functions show that they are worthy of the holy office they exercise. It will also be fitting that singers while singing in church wear the ecclesiastical habit and surplice, and that they be hidden behind gratings when the choir is excessively open to the public gaze.