Acclamation of the Latin Mass, sung between the Fraction and the communion antiphon. Since the text does not change from day to day (except for the Mass for the Dead), the Agnus Dei is counted as part of the Ordinary of the Mass. Many chant settings were made between the 11th and 16th centuries. Some of the most widely used were included in the Liber usualis.
Apart from the Credo, the Agnus Dei is the most recent of the acclamations of the Latin Mass, and in some respects the least firmly entrenched. It seems to have been added to the Mass as a confractorium (or chant to accompany the breaking of the bread) late in the 7th century, perhaps by Pope Sergius I. The text itself is from John i.29: ‘Behold, the Lamb of God, who takes away the sin of the world!’; but the specific association of the sacrificial lamb with Christ in the Eucharist and on the altar seems to be characteristic of Syrian practice of the early centuries. In any case, the direct address to the Son, found here as well as in ‘Christe eleison’ and in the christological portion of the Gloria in excelsis, contrasts with the Roman habit of addressing only God the Father in prayers of the Mass. Other rites (Ambrosian, Mozarabic), however, had other confractoria.
As long as loaves of leavened bread were used, the Fraction occupied an appreciable space of time, during which the petition, ‘O Lamb of God, that takest away the sins of the world, have mercy upon us’, was repeated an indefinite number of times (Ordo romanus I/III), presumably either antiphonally or with the people responding with the last phrase. With the substitution of small units of unleavened bread, the Fraction occupied only a moment, and the Agnus Dei, after a period of uncertain transition, took on other functions: it was most often associated either with the Kiss of Peace, or with the administration of Communion immediately following. During this same period (10th–12th centuries) the number of petitions gradually established itself at three, and ‘dona nobis pacem’ was substituted for the third ‘miserere nobis’, having the same number of syllables and pattern of accents.
The period of liturgical transition happened to coincide with that in which the medieval repertory of Agnus Dei chants, together with their tropes, came into being. Many questions regarding musical practice in this period have still to be settled on the basis of the early documents, especially the tropers. For example, while the latter usually indicate the dovetailing of tropes and Agnus Dei by the cue for ‘miserere (nobis)’, variously abbreviated, they often omit reference to one or more repetitions of Agnus Dei altogether. Common opinion, and perhaps common sense, ascribes this omission to mere abbreviation and assumes that the ‘standard’ text of Agnus Dei remains intact, the tropes being added to it (but in ways not yet made clear). Given the instability of the Agnus Dei at that time, however, and given its open-ended litany-like nature earlier, it seems at least possible that the tropers faithfully preserve an actual practice, one in which one or more of the invocations ‘Agnus Dei, qui tollis peccata mundi’ was actually replaced by a trope, only the ‘miserere nobis’ remaining as a response – a practice analogous to some Kyrie ‘tropes’.
In any case, the picture presented by the manuscript sources for the Agnus Dei chants does not always support the impression given by the Liber usualis of a carefully moulded threefold arch form with contrasting middle section. The second and third acclamations may vary in different sources, or be missing entirely, which (together with the hints in the tropers) suggests that a continuing ad libitum repetition might have been practised well into the later Middle Ages. It is true that the threefold form is most often ABA (tabulation in Schildbach, p.32), but the form AAA is frequently found too, to which may be added variants such as AA'A, in which the ‘miserere nobis’ often remains constant, pointing again to a litany response.
The most popular melodies are generally well represented in the repertory in the Liber usualis (but it must be studied only in conjunction with Schildbach's catalogue). Agnus Dei II/Schildbach 226, IX/114, XV/209, XVI/164 and XVII/34 best represent popular medieval practice from the 11th century onwards; of other early melodies, while IV/136 was widely disseminated, VI/89 is more characteristic of German than French sources, while III/161 is known only from a handful of German sources. On the other hand, some fairly well-known early melodies (Schildbach 64 and 78, French; 81, Italian; and 236) were not included in the Vatican edition. As with the Kyrie and Gloria, the simple melody XVIII/101, usually presumed the earliest, has an unconvincing manuscript representation; but it may still reflect an early tradition, mainly because the same melody is found also in the Agnus Dei in the received chant for the Litany of the Saints. In any case, it has little to do with the more elaborate, antiphon-like melodies represented by Agnus Dei II/226. The high degree of moulding within the construction of any single acclamation in Agnus Dei IX/114 or III/161 seems indigenous to chant styles of the 11th century and after, when beautifully shaped phrases tended to prevail over other aspects of composition. Whereas the majority of melodies up to the 12th century are in D- or G-mode, a large proportion of late medieval melodies, particularly from Germany and Eastern Europe, favour the E- and F-modes (tabulation in Schildbach, pp.45–7), with notable emphasis of the 5th and octave as melodic goals. Over a quarter of the later compositions are identical or share material with Sanctus melodies (Schildbach 51–6).
Polyphonic settings are known from the 12th century onwards (editions in Lütolf).
MGG2 (C.M. Atkinson)
O. Marxer: Zur spätmittelalterlichen Choralgeschichte St Gallens: der Codex 546 der St. Galler Stiftsbibliothek (St Gallen, 1908) [with edn of many late medieval Agnus melodies]
M. Sigl: Zur Geschichte des Ordinarium Missae in der deutschen Choralüberlieferung (Regensbrug, 1911) [with edn of many late medieval Agnus melodies]
J.A. Jungmann: Missarum sollemnia: eine genetische Erklärung der römischen Messe (Vienna, 1948, 5/1962; Eng. trans., 1951–5/R as The Mass of the Roman Rite)
R.L. Crocker: ‘The Troping Hypothesis’, MQ, lii (1966), 183–203
M. Schildbach: Das einstimmige Agnus Dei und seine handschriftliche Überlieferung vom 10. bis zum 16. Jahrhundert (Erlangen, 1967)
M. Lütolf: Die mehrstimmigen Ordinarium Missae-Sätze vom ausgehenden 11. bis zur Wende des 13. zum 14. Jahrhundert (Berne, 1970)
C.M. Atkinson: The Earliest Settings of the Agnus Dei and its Tropes (diss., U. of North Carolina, 1975)
C.M. Atkinson: ‘The Earliest Agnus Dei Melody and its Tropes’, JAMS, xxx (1977), 1–19
G. Iversen, ed.: Corpus troporum, iv: Tropes de l'Agnus Dei (Stockholm, 1980) [edn of trope texts]
C.M. Atkinson: ‘O amnos tu theu: the Greek Agnus Dei in the Roman Liturgy from the Eighth to the Eleventh Century’, KJb, lxv (1981), 7–31
D. Hiley: ‘Ordinary of Mass Chants in English, North French and Sicilian Manusripts’, JPMMS, ix (1986), 1–128
J. Boe, ed.: Beneventanum troporum corpus, ii: Ordinary Chants and Tropes for the Mass from Southern Italy, A.D. 1000–1250, pt 4: Agnus Dei, RRMMA (in preparation)
RICHARD L. CROCKER/DAVID HILEY