Dissertation Index

Author: Gerlach, Oliver

Title: Im Labyrinth des Oktōīchos — Über die Rekonstruktion einer mittelalterlichen Improvisationspraxis in der Musik der Ost- & Westkirche

Institution: Humboldt University

Begun: December 2001

Completed: July 2006


The title “Im Labyrinth des Oktōīchos (In the Labyrinth of the Oktōēchos)” refers to the spatialisation of a two-dimensional, hand-drawn image known as the “Koukouzelian Wheel” (trochos tou Koukouzelē). This image is the key to a musical art of memory which developed in the context of the kalophonic art of chant (psaltikē technē) in the school of Iōannēs Glykys at the end of the thirteenth century. Arabic representations of the tonal connections between melodic models (naġme) in the form of wheels and trees also exist from this time. The form of the wheel represents a tonal system in which every tone can be the centre of every mode — a network of tonal relationships beyond the imaginary capabilities of musicians, who therefore can use the wheel to help guide them along even the most complex of paths through the labyrinth without losing their sense of orientation. Previous research regarded the trochos as an unsolved puzzle. This first attempt to solve the puzzle throws up several questions, of which many will only be answered after further research work.

By comparing the different sources handed down from the ninth to the twelfth century, the uniquely Carolingian practice of prohibiting “the shift in position of the semitones and whole tones”, in other words transpositions (metavolē kata tonon), is explored as a means to arrive at a clear modal classification. In contrast to the wheels used in the Arabic-Persian and Greek traditions, where the melos in solo forms not only pass through several modes but in fact through several transpositions of the entire system of reference, the Latin reception represents a radical simplification in music theory. This simplification has at the same time had a real impact on musical thinking right up to the present day, to the extent that many of the problems that arise when trying to understand the “wheel” must be approached with this impact in mind: in other words, even today musicians in Spain and northern Africa, as well as in the Balkans and the Middle East, do not have this difficulty because their own traditions are more deeply rooted in Ancient Greek music theory, because they use the three forms of the metavolai (in addition to transpositions, changes of the mode and the tone system).

In liturgical music from Christian traditions, the crisis of the iconoclasm proves to be a caesura in the transmission of music: both the Byzantine and Roman traditions draw on the eight mode system of Jerusalem (oktōēchos). The present study compares Latin sources from Aquitaine, which researchers of Gregorian music have classed as rather “unreliable” due to their many deviations from the “norm”, with Byzantine sources (from Italy and Constantinople in particular). Byzantine notation, which describes the degrees of the mode and their ornaments, draws at a basic level on modal signatures used to designate the main mode by a main signature but also the other modes by medial signatures that particular song forms pass through in their melos. Their transmission can be described as “soft”, meaning that the tone or phonic neumes present only the bare bones of the chants, the interpretation of these (thesis of melos) then taking place in accordance with the homogenous set of forming principles used in a local tradition and its school. Latin neumes, on the other hand, write out the melos, since the Carolingian reform necessitated that a repertoire which was ten times as big be communicated to cantors in the Empire, and since the reformed chant used so many regional traditions (including Byzantine) it is practically impossible to find a unified form of the melos using comparative analysis. These chants were first notated and only then classified modally, using brief appendices known as tonaries, which are ordered according to the 8 modes (toni) and which in particular present the incipits of antiphonal chants after the intonation and psalm formulas for the mode in question.

Compared to the editorial decisions taken by Carolingian cantors in the ninth century, those in the three theoretical tonaries, which are known as alia musica, are markedly different: the names of the intonation formulas and the descriptions of the mictrotonal shifts in the leading degrees of a mode (melodikeis elxeis) suggest that these were in some cases adopted from Byzantine cantors for the purpose of being able to use particular melos forms from the Greek ēchoi on particular chants in the Latin repertoire. They are thus particularly interesting for scholars of Byzantine music, since there is not a single theoretical source for this music surviving from the period in question.

The intonation formulas in the Latin tonaries and in the modal signatures of Byzantine notation are also worthy of particular attention since singers could used them to develop longer forms through a restricted form of improvisation (Chapter 2).

As examples for forms such as these in Byzantine sources, the kalophonic expansions of the stichērarion and later the heirmologion are discussed, as well as the development of the cherouvikon from the choir book of the old cathedral rite (thirteenth century) up to the use of all 8 ēchoi in the cycles of today’s songbooks. Here, in archaeological fashion, it is necessary to proceed from today’s living tradition — documented through my own and also existing fieldwork — to the earlier traditions, by revealing each individual layer of transmission. Due to the “soft” transmission practice of the older manuscripts, even traditional singers have today only a very vague idea of the historical forms of the melos and the different methods of the thesis that are to be used for these sources (Chapter 3).

Since Latin neumes in contrast write out the melos, they develop their long forms as a reshaping of an existing melos, as in the form of the florid organum for two voices. Here, the study concentrates on the ars organi as transmitted as an improvisatory art in the Vatican Organum Treatise, rather than on the written alterations to this art in the late revised manuscripts of Leonin’s Magnus liber organi, which still survive today (Chapter 4).

The study is supplemented by a description of my own experiments in the area of performance practice (Chapter 6), which deal with the difficult material of the Missa greca (Chapter 5). The study is completed with a discussion of the liturgy as an aspect of the musical art of memory (Chapter 1) and of the need for further research in systematic musicology on modal musicianship (Chapter 7).

Since the study calls into question many familiar ideas about music theory and history held by musicologists and blurs the boundaries of what is still regarded as the “history of Western music” (the impact of this being felt in university curricula and in the formation of “BA modules” in undergraduate study), the author expects that the study will provoke productive discussions with colleagues in all related fields. The path is laid for these discussions by an introductory overview of the theory of transmission, a subject which has been hotly debated with regard to the interpretation of sources in the last few years.

Keywords: Koukouzelian Wheel (trochos tou Koukouzelē), Oktōēchos, methods of the thesis of the melos, tonesystems (systēma teleion, systēma kata tetraphonian, systēma kata triphonian), genus (diatonic, chromatic, enharmonic), metabolē (metabolai kata tonon, kata genon, kata systēma), mode, ēchos (glas, sonus), phthongoi (voces), great signs (megalai hypostaseis, megalai sēmadia, cheironomies, aphones), phthorai (nana, nenano, müstear, hisar, nisabur),
modal signature (medial, main signature)




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