Chapter III-3. Books of Liturgical Chant.

56. The standard editions of the liturgical chant of the Roman Church are:
Roman Gradual, with the Ordinary of the Mass.
Roman Antiphonal, for the Day Hours.
Offices of the Dead, Holy Week, and Christmas.

57. All publication rights to the Gregorian melodies as they appear in the liturgical books approved by the Roman Church are the property of the Holy See.

58. The following decrees of the Sacred Congregation of Rites remain in force:
Instruction on the Publication, and Approval of Books Containing the Gregorian Liturgical Chant, Aug. 11, 1905 (Decr. Auth. SRC 4166)
Declaration Concerning the Publication and Approval of Books Containing the Gregorian Liturgical Chant, Feb. 14, 1906 (Decr. Auth. SRC 4178);
and the decree which treats of particular questions regarding the approval of books containing the chant for the "Propers" of certain dioceses, and religious congregations, issued Feb. 24, 1911 (Decr. Auth. SRC 4260).

The rules established by the Sacred Congregation of Rites on Authorization to Publish Liturgical Books, Aug. 10, 1946 (AAS 38 [1946} 371-372), also apply to books of liturgical chant.

58. Thus, the authentic Gregorian chant is that which is published in the standard Vatican editions, or which has been approved by the Sacred Congregation of Rites for a particular church or religious community. Publishers who have this authorization are obliged, therefore, to reproduce both the melody, and the text exactly as approved in all details.

The rhythmic signs which have been inserted into some chant editions on private authority are permitted so long as they not alter the melodic line of the grouping of the notes, as they appear in the Vatican editions.