sacramentary of St. Gregory the Great, the formula appears but once, and then in the words of the formula used at Mass: "Agnus Dei … mundi, miserere nobis". The use of the formula in litanies is of comparatively recent date.
It remains to say a word about the musical settings of the Agnus Dei in the Mass. Originally, of course, the melody was plainsong, doubtless very simple and syllabic at first, and subsequently developed into richer forms. Recent studies in musical palæography have succeeded in rescuing the ancient melodies from oblivion, and in the Vatican "Kyriale" (1905) we find twenty settings substantially reproducing the ancient texts. These melodies range from the syllabic up through various grades of the florid into moderately melismatic chants. A rough idea of the melodic forms may be gained by considering that there are eighteen syllables of text in any one of the three invocations, and that the number of notes accompanying any one of these invocations of eighteen syllables ranges from nineteen (in which case only one syllable of the text can receive two notes) up to sixty-one (as in No. V of the "Kyriale"). In No. V the first syllable has nine notes, however; and a mere enumeration of notes is not sufficiently descriptive of the character and flow of the melody, although such enumeration will help towards forming an idea of the melodic richness or poverty. The familiar melody of the Requiem Mass Agnus Dei, with its twenty notes to eighteen syllables, will illustrate a purely syllabic chant, and will serve to explain its assignment to days of penitential character, such as the ferial days in Lent and Advent, Ember and rogation days, and vigils, to which the "Kyriale" nominally assigns it. With respect to the variety of melody offered in the triple invocation, we find six masses (nos. I, V, VI, XVIII, XIX, XX) in which the melody remains the same for all three invocations—a form which might be indicated as a, a, a; twelve masses in which the melody of the first and third Agnus Dei are identical, but the second different—type a, b, a; one mass in which the first two are identical, while the third varies—type a, a, b; and one mass in which all three are different (No. VII)—type a, b, c. In type a, b, a, however, many correspondences of melody between a and b are found in certain potions of the text; while in type a, b, c, the melody of "nobis" is common to all three. In all this we can perceive the operation of excellent ideas of symmetry and form amid great variety of melody. The plainsong melodies of the Agnus Dei (as, indeed, of other chants as well, the Kyries exhibiting similar obvious symmetries, while the more melismatic chants of the Proper of the Mass will, under enlightened analysis, yield surprisingly beautiful results) are illustrations of the fact that the ancient composers, although working under very different conceptions of music from those which obtain in our days, had clear perceptions of the province of form in musical art, and had canons of construction and criticism which we have not as yet, in all likelihood, fully appreciated [Wagner, "Einfuhrung in die Gregorianischen Melodien" (Freiburg, Schweiz, 1895), 247–250; also, in the Philadelphia quarterly, "Church Music", June, 1906, 362–380, two articles on the Introit: "Gaudeamus omnes in Domino", and March, 1906, 222–232, the article on the "Hæc dies"].
The text of the Agnus Dei, triple in repetition, and, therefore, possessing its own rights of textual symmetry, was respected by the medieval composers; and the one fact which, in this respect, discriminates their forms of treatment from those of the master-composers of modern church music, is the absence of any separate treatment of the "Dona nobis pacem", that grand finale movement in which the moderns have been so accustomed to assemble all their energies of technique, voices, and instruments, and to which they assign a movement entirely different from the preceding one. Familiar examples of this are found in Bach's great Mass in B-minor, where the first two Agnus Deis are alto solos, followed by the "Dona" in four-part fugue. Significant of the musical and liturgical aloofness of the "Dona" from the Agnus Dei in this composition, is the fact that no third Agnus Dei occurs at all. In Beethoven's monumental Mass in D, solo and chorus sing the "Agnus … nobis" thrice adagio, the "Dona" forming a new movement in allegretto vivace and requiring more than three times as many pages as the thrice-repeated "Agnus"; so, too, in his Mass in C, the "Dona", allegro ma non troppo, takes thrice as many pages as the whole preceding text in poco andante. So, too Haydn's "Third" ("Dona", allegro vivace, twice as many pages as all the rest adagio); his "First" ("Agnus", adagio, strings only—"Dona", allegro, oboes, trumpets, tympani, and strings); his "Sixth" (Agnus", adagio, 34—"Dona", allegro con spirito, 44); his "Sixteenth" ("Agnus", adagio, 44—"Dona", allegro, 34, strings, clarinets, trumpets, tympani, and organ). Illustrations might be multiplied without number from other masses, of Mozart, Schubert, and the rest. A very interesting exception is found in the masses of Gounod (quite naturally, in view of his training and polyphonic studies), which respect the triple symmetry of the text; and we find in his "Agnus" almost the primitive plainsong symmetry. Thus, his second mass of the "Orphéonistes" gives us the type a, a, b; his first of the Orphéonistes, the type a, b, c (agreeing, curiously enough, with the single illustration of that type in the "Kyriale", in having for the two "nobis" and the "dona" the one musical formula); his "Sacred Heart Mass", the type (with slight variations) a, b, a; his "St. Cecilia" (omitting the interpolation of the "Domine non sum dignus," etc.), the type a, a, a (with slight variation). Gounod's interpolation of "Domine non sum dignus" has been very severely criticized as a great liturgical offence—and so it is; but it is additionally interesting to note, even there, an echo of the medieval custom spoken of in the preceding part of this article, of the trope-treatment of the liturgical texts. Gounod's trope was built up out of his own fancy, but was at least wholly liturgical in the selection of the intercalated text; it was also singularly appropriate to the portion of the Mass then reached, namely, the Communion of priest or of people. Of the quasi-dramatic treatments which the Agnus Dei has received in modern times, it is not worth while to speak (e.g. Haydn's Mass in tempore belli, Beethoven's in D, with the roll of drums accentuating the blessings of peace in contrast with the horrors of war), or of the treatments which have thoroughly disfigured, by omissions, insertions, and additions of words, the beauty of the liturgical text; or have so interposed the words as to make nonsense (e.g. Poniatowski's "Mass in F"—to select from the lesser order, which indiscriminately assigns to each of the "Agnus … mundi" a confused jumble of "miserere" and "dona"—a conceit, the symbolism of which is not clearly intelligible). In general, these liturgical excesses resulted from the dramatic instinct working in the field of sacred music.
Agonistici (Gr., ἀγών=struggle), one of the names given by the Donatists to those of their followers who went through cities and villages to disseminate the doctrine of Donatus. They first appeared about 317 (Tillemont, Mém., VI, 96), and claimed that they were champions of Christ, fighting with the sword of Israel. Their war-cry was Laudes Deo (Praises to God). They committed many barbarous acts and deeds of violence. Whether they
