The name of several medieval musicians whose identity has been confused. A tonary and treatise of the late 10th century attributed to ‘Abbot Odo’ may be regarded as the work of an Abbot Odo of Arezzo (see §2), rather than Abbot Odo of Cluny, composer of hymns and antiphons (§1). A Dialogus on music has been attributed to the latter, but it is more probably an anonymous treatise of north Italian provenance (§3). Another tonary, probably of Franciscan origin, has also been wrongly attributed to ‘Abbot Odo’ (§1), and a simple monk of Cluny named Odo has been confused with Abbot Odo of Cluny (§1). A further tonary, De modorum formulis, dating from the 11th century, is an anonymous work showing the influence of Odo of Arezzo and the Dialogus(§4).
Odo, Abbot of Cluny, was born in the Maine in 878/9 and educated by Remigius of Auxerre. He succeeded Berno (d 927), the first abbot of Cluny, and died at Tours on 18 November 942. Besides sermons and biblical commentaries, he wrote three hymns (Rex Christe Martini decus, Martine par apostolis and Martine iam consul poli) and 12 antiphons for the monastic Office of St Martin on 11 November (AH, 1, 1907/R, pp.264–8; ed. J. Szövérffy, Die Annalen der lateinischen Hymnendichtung, i, Berlin, 1964, pp.320–23). Odo's authorship of these hymns and antiphons was attested by his first biographer, John, who noted that they were still sung at Benevento (‘retinentur hactenus Beneventi’, PL, cxxxiii, 48c).
Although these antiphons are not found in the antiphoner of St Lupo at Benevento (CAO, ii, no.116), the complete series survives in the noted Cluny breviary (F-Pn lat.12601, f.153) and in French and Italian Cluniac antiphoners (Pn lat.12044, f.203v; I-Rc 54, f.74v–75). They were subdivided into three phrases with cadences (‘ternas per singulas habentes differentias’). The antiphon O beatum pontificem (CAO, iii, no.4002) quoted in the anonymous Dialogus falsely attributed to Odo (GerbertS, i, 256), there said to have been corrected musically by ‘Abbot Odo’, is not one of these antiphons but is a part of the ancient Gregorian repertory.
The likelihood of Odo's authorship of the Dialogus (GerbertS, i, 252ff, attributed in several manuscripts to ‘Odo’ or ‘Odo abbas’) is further reduced since his first two biographers (De viris illustribus, PL, clx, 573) did not list it among his works; neither did it survive among the writings of the abbots of Cluny even though the abbey library was scrupulously maintained during the 12th century (see L. Delisle: Le cabinet des manuscrits de la bibliothèque impériale, ii, Paris, 1874, p.469, nos.300–14).
The various tonaries falsely attributed to ‘Abbot Odo’ (see Huglo, Les tonaires, 1971, pp.183–5) include a 14th-century Intonarium a domno Odone abbate diligenter examinatum et ordinatum (F-SDI 42: CoussemakerS, ii, 117–49). However, the prologue of this tonary borrows from the Franciscan ruling of before 1254 concerning noted chant books (see M. Huglo: ‘Règlement du XIIIe siècle pour la transcription des livres notés’, Festschrift Bruno Stäblein, ed. M. Ruhnke, Kassel, 1967, pp.121–33) and quotes an antiphon of St Francis; it is, therefore, of Franciscan origin (see Huglo, Les tonaires, 184).
Before he was elected abbot, Odo had discharged the functions of magister scholae. Another monk also called Odo, but a simple deacon (‘Oddo levita’), was the scholae cantorum magister at Cluny in 992 (see A. Bruel, ed.: Recueil des chartes de l'abbaye de Cluny, iii, Paris, 1884, p.145).
A tonary with a discussion of the modes is preserved in about 20 manuscripts, of which four specifically attribute the composition of the text to ‘the religious lord Abbot Oddo who was skilled in the art of music’. The Proper chants in the tonary, with their frequent references to Bishop Donatus of Arezzo, indicate that this ‘Abbot Oddo’ compiled his work at Arezzo in the late 10th century. Although several different versions of the text exist, some of them originating in monasteries considerably distant from the city, the association with Arezzo is evident even in those versions that show substantial modification (see Huglo, Les tonaires, 1971, pp.223–4).
The prologue to the tonary, ‘Formulas quas vobis’ (GerbertS, i, 248–9), is contained in only six tonaries, all of central or southern Italian origin; three of these contain ascriptions to Odo. The lack of ascription to Odo in the other sources does not mean that he was not the author: successive revisers of his work would not necessarily name the original author of the text. The work is given no title in the extant manuscripts and its initial word, ‘Formulas’, suggests a description of modal formulae rather than specifying a tonary. However, several treatises by Guido of Arezzo use phrases such as ‘formulae modorum/tonorum/super tonos’ and ‘in modum formulis’, or simply the word ‘toni’, to refer to a tonary, unlike ‘regulae’ which, unqualified, could signify a treatise on music theory. Merkley's contention that the prologue might be a later accretion is based on the announced intention of the prologue to reform the modal assignments of the chants and the subsequent demonstration that the antiphon O beatum pontificem (cf §1 above) should be classified as tone 1 rather than tone 2 and assigned to differentia 7 (see Merkley, 31). Although this emended tonal designation is followed in several Italian tonaries and one from southern France (F-Pn lat.7185), all of them associated with the prologue (or vice versa), none assigns the majority of its antiphons in the same melodic class as O beatum pontificem to differentia 7. The emendation itself, however, was transmitted into the 12th century as the prototype of the ‘revised’ modal formula in the De modorum formulis tonary (see §4 below). The number of differentiae in the prologue in I-MC Q318, pp.125–7 (GerbertS) agrees in each of the eight tones with the tonary that follows in the same manuscript.
The surviving sources of the tonary fall into three classes (see Huglo, Les tonaires, 186–204): (1) versions of the text containing only minor modifications of the original, for example, I-MC Q318 (first tonary), the earliest dated in this group; (2) interpolated versions; and (3) texts deriving from (1) but which do not form a single textual family and contain numerous modifications that distance them from both (1) and (2). The texts of the surviving sources are too disparate and too heavily modified (notably in tones 2, 4 and 5) for a faithful reconstruction of Odo's original text to be tenable, although a comparison of the extant manuscripts would provide some idea of what he might have written. Merkley has suggested that each version of the text may have followed its own individual and independent path, thereby invalidating both the construction of stemmata for the tonary and its prologue and the positing of a tonary archetype (Merkley, 32, 56). He does not, however, take into account the existence of ‘active texts’ (Huglo, 1979, p.309) – those used primarily for instruction and modified at the discretion of the magister – such as the theory manuscript of Martin Bodmer (CH-CObodmer 77), which is swollen with magisterial accretions.
Both I-MC Q318 (first tonary) and Fs (see Huglo, Les tonaires, pl.III) contain the ascription to Odo, the former proposing to assign antiphons to differentiae under their respective modal ‘formulae’ – presumably the echemata. Merkley has approached a reconstruction of the original text by examining seven large representative Italian tonaries and comparing the classification in them of Office antiphons according to their respective differentiae with the assignment in the first tonary of MC Q318 (see Merkley, 161–236). His analysis shows that the correspondence is greatest – a total of 423 antiphons – in the two tonaries bearing Odo's name. Next in order of compatibility, with 73 correspondences, is GB-Ob 25, from central Italy near the Beneventan zone (Huglo, Les tonaires, 197), followed by CH-CObodmer 77, I-Fn conv.soppr. F III 565, Lc 603 and MC Q318 (second tonary), which includes the tonus peregrinus. From this examination of successive versions of the tonary, it is clear that although the original Odonian text has undergone substantial revision, it has nevertheless survived in the distribution of the majority of the antiphons to the 41 differentiae proposed by Odo.
A Dialogus on music is attributed in a dozen manuscripts as in Gerbert's edition (GerbertS, i, 252–64) to Odo. This treatise, compiled in the province of Milan, came to bear this attribution because the author mentioned that Abbot Odo had corrected the antiphon O beatum pontificem for modal reasons; an Italian or German copyist then came wrongly to ascribe the whole treatise to Odo (see Huglo, 1969). The Odo in question here is in fact Odo of Arezzo rather than Odo of Cluny. (See also §1.)
The Dialogus (partial Eng. trans. in StrunkSR1, 103–16) consists of 18 chapters and deals with the division of the monochord (1–2), the intervals (3–5) and the modal system (6–18). This treatise is one of the earliest datable documents using the term ‘gamma’ with reference to the monochord, although it occurs in the Musica enchiriadis (late 9th century) as the name of the lowest note of the gamut (gamma ut; see Meyer, p.xxix). The active diffusion of the monochord measurement of the Dialogus was widened by its association in manuscripts that circulated Guido's texts, and its ascending progression through two successive tones was continually adopted into, for example, organistrum tuning (Meyer, pp.xlii, lviii). Another treatise, Musicae artis disciplina (GerbertS, i, 256ff), shares much of the content of the Dialogus and is regarded by Oesch as an earlier version.
In nine of the manuscripts, the Dialogus is preceded by a prologue (GerbertS, i, 251–2; ed. Huglo, ‘Der Prolog’, 1971, pp.138–9). This had a separate origin and was apparently composed for an antiphoner with alphabetic notation, only later coming to be attached to the anonymous Dialogus. Guido of Arezzo drew on this prologue for his Prologus in antiphonarium and even for the prologue to his Micrologus.
The anonymous tonary known as De modorum formulis (ed. Brockett), composed during the second half of the 11th century, shows the influence of the work of Odo of Arezzo and the anonymous Dialogus de musica, which was closely associated with Guido of Arezzo (b c990) though not written by him. De modorum formulis probably originated in central Italy and subsequently spread northwards. The untitled preface to the tonary, ‘Vocum modus’ (Brockett, 46–56), is known to have been preserved in five sources: the manuscript at St Blasien, now lost, that Gerbert used in his preparation of the text (GerbertS, ii, 37a–40b, there attributed to Guido); F-Pn lat.10508 (CoussemakerS, ii, 78a–81a; published without the figure); I-MC 318, pp.208–14 (see Brockett, pl.I), in which it is widely separated from Odo of Arezzo's prologue ‘Formulas quas vobis’ on p.127; Fl Ashb.1051, ff.67r–68r; and CH-CObodmer 77, ff.109v–111r. The last three sources are fragmentary.
The rationale of music theory found in the prologue was influenced by Remigius of Auxerre's commentary on book 9 of the De nuptiis Philologiae et Mercurii of Martianus Capella and by the works of Guido of Arezzo, especially the Micrologus (c1030; see esp. chaps.6, 8, 12 and 16) and the Epistola de ignoto cantu directa (also known as Epistola ad Michaelem; GerbertS, ii, 43–50; see Brockett, 7–17, 19, 21). The most Guidonian aspects of the prologue are the designation of differentiae (‘formulae’ in the text) in relation to the initial pitches of the chant (differentiae with melodies higher than the initial pitch are classified as praepositivae; those that are equal are termed appositivae; and those that are lower are suppositivae) and the categorization of chant melodies accordingly within each of the eight tones. Guido's terminology – praepositae, appositae and suppositae – was almost identical to that of the prologue and was adopted in the following tonary; however, Guido's designation of two further categories of ‘motions of notes’, namely the interpositae and mixtae, are not used in the tonary.
The author of the De modorum formulis differs from Guidonian theory in his use of a three-tetrachord complex – mediae (finales), bordered by graves and acutae – adapted to the eight tones; the Micrologus (chap.11) employs a four-tetrachord standard, including the superacutae. The author also uses C rather than Guido's A as the orientation pitch. Such differences and the paucity of evidence linking Odo with the work makes it unlikely that he was the author of De modorum formulis. However, the correspondence between the prologue and the tonary suggests that they were originally intended to be together.
The tonary (Brockett, 57–128) is identified in precisely those sources designated in class (2) above (see §2): F-Pn lat.10508 (CoussemakerS, ii, 81a–109b, but with misinterpretations and inaccuracies); GB-Ob Digby 25; I-Rvat Reg.lat.1616; GB-Lbl Add.10335 (lacking tones 1 and 2); the St Blasien manuscript, no longer extant, used by Gerbert (GerbertS, ii, 41a–b), which contained only the introduction leading up to the formula of tone 1. These sources are remarkably consistent in their assignments of differentiae and the ordering of antiphons within each category, but they diverge considerably from the ordering characteristic of class (1). For example, in the longest list of antiphons – which occurs in tone 1, differentia 1 – the sources containing the De modorum formulis (class 2) all present a similar order of antiphons, although the total number of chants varies; the manuscripts with the two Odonian texts (class 1) disagree radically with the class 2 sources and with each other (see Brockett, 163–5). A process of codification appears to have occurred between the 11th and 12th centuries that produced the more consistent list of the De modorum formulis.
The treatment of the differentiae, which are described in the prefaces to each tone and notated in the tonary proper, respects to a certain extent the tradition transmitted by Odo of Arezzo's tonary and its preface ‘Formulas quas vobis’. The discrepancies probably result from the arbitrary categorizations that situate them above, below, or apposite with the antiphon intonation; they occur in tones 2, 4 (with six differentiae, but its preface stating nine), 5, 7 and 8 (with four differentiae, but the preface delineating six). Tone 1 appends three additional differentiae, evidently for the adjustment of dubious assignments to this tone; tone 2 appends one, perhaps intended to accommodate antiphons intoned and terminating on the upper 5th like its specimen. The tonary contains 689 Office antiphons, 146 introits, 97 communion antiphons, 11 responsories and 9 responsory verses (Brockett, 162).
RiemannG
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MICHEL HUGLO (1, 3), CLYDE BROCKETT (2, 4)