An additional circumstance which supports the theory of Greek origin is the fact of musical parallelism in the structure of the sequence. This is an important point of contact between the sequence and Byzantine musical forms, although it has not been universally convincing. On the contrary, some have traced this phenomenon of musical parallelism to one of those extraneous conditions, affecting liturgical practice, namely, the use of antiphonal choirs.[16]
Nothing can be more unsatisfactory to the student who is trying to force the sequence into any particular theory of musical origin than the contemplation of what is actually known on this subject, for the question seems destined to remain undecided. A better perspective may be reached by examining the poetical development of the sequence which began with the sequentia cum prosa and ended in a new form of Latin hymn for which melodies were in turn composed.
The text written below the alleluia melody is generally accepted as of French origin and likewise the naming of that text. As the text became important the melody too was named so that the melody and text were differentiated from each other, the latter as a prosa. It is unknown whether the name sequentia instead of prosa was chosen deliberately as differing from the French usage. Amalarius was apparently the first to use the word sequentia in connection with the music. Later the term was destined to supersede the name prosa for the poetical text.
We owe to Notker, whose part in creating the sequence will be considered in greater detail below, an account of his invention of words as an aid to memorizing the elaborate melody of the alleluia trope. Whether Notker was the first to see the value of this device and to employ it, is unknown.[17] As a theory of origin it has always been popular, being held by Frere and many others. For the present it may be acknowledged that it is a reasonable theory for, of course, only the choir leader had a musical codex to refer to and the musical ability of the average monk was unequal to the difficulties of memorization by ear alone. Moreover, this theory can always be accepted with others, although it seems inadequate by itself.
A second explanation of origin arises from the possibility that sequence poetry originated in the imitation of Greek hymn models. The statement has been made definitely that sequence poetry shows the transference of the Byzantine structure of hymnody to Latin church poetry, especially Notker’s.[18] With every circumstance favoring such a transfer it is amazing that the Franks who heard so much of Greek hymns and could have translated them into Latin and sung them to the same tunes, evidently did nothing of the kind. Some other explanation of similarity must be found. Metrical parallelism, which is characteristic of the Latin sequence and contemporary Greek hymns, in Gastoué’s opinion, can be accounted for only by reference to Hebrew poetry as the ultimate inspiration of liturgical poetry.[19] Thus a Byzantine theory of origin breaks down when metrical sources are subjected to closer scrutiny. After all, the sequence is unknown in the Byzantine ritual and therefore the Byzantine influence could never have been direct.
A third theory emphasizes the metrical form of the alleluia melody as the determining factor in creating a new poetical rhythm.[20] Here, the desire to create fitting expressions of praise is not explained so much as the form in which the praises are cast. Von Winterfeld thought that rhythmical prose was inseparable from the liturgical music which had already been composed, just as the Greek chorus and the Wagnerian music drama found their complement in a dignified and sonorous prose rhythm.[21] This theory may well be called the liturgical. It is most significant for the lyrical movement in general since a new metrical form is created differing from the Ambrosian meter or the revived classical meters popular among Carolingian poets. The lyric is born again, as Meyer expresses it, in the music of the church.[22] A poem arises consisting of a series of parallel strophes with introduction and conclusion, a lyric counterpart to the musical phrases of the sequentia.
II. Sequences of the German School
The importance played by St. Gall in the development of the sequence has given rise to the theory that it originated there. Present-day opinion, as indicated above, concedes that sequences arose in France and that St. Gall is not a place of origin but like St. Martial, a prominent center for their composition and diffusion. Other centers were Metz, Murbach, Fulda, Echternach, Kremünster and St. Florian. Reichenau, too, was important in music and in the spread of sequence poetry.[23]
Notker Balbulus, (840?-912), was largely responsible for the enviable reputation enjoyed by St. Gall. Born in Switzerland, Notker had entered the Benedictine monastery at St. Gall as a child to be educated and there he continued as a member of the Order until his death. A pupil and later a teacher of the music school in the period of Louis the Pious and Louis the German, he shared the life of the Abbey during the height of its reputation, when its doors were open to travelers from every land and every rank of society. Notker himself tells of the refugee from the French monastery of Jumièges who brought with him his famous Antiphonary. Tradition has it that Notker composed words to fit the forms of the alleluia-iubilus, note for note, already in use in his monastery, and thus originated the sequence, finding his inspiration, not in the Ambrosian hymns but in the liturgy.[24] The Jumièges Antiphonary reached St. Gall about 860, by which time prosae were already known in France. There is evidence, moreover, from manuscripts, that texts existed before Notker’s time in St. Gall. He is not their first composer nor are the sequences emanating from St. Gall necessarily all Notker’s work. “Notkerian” means for sequences what “Ambrosian” means for hymns.
The problem of the authentic Notkerian sequences was subjected to critical study and variously solved by Schubiger in 1858, Wilmanns in 1872, and Werner in 1901. More recent students have re-examined the evidence and expressed their critical opinions as to Notker’s poetical and musical prestige: Singer in 1922, Van Doren in 1925 and Clark in 1926. Of more than 100 sequences attributed to Notker, 47 were judged to be authentic and edited in volume 53 of the Analecta Hymnica. Notker’s ability as a musician appears to be a matter of controversy. A new review of the Notkerian problem and its literature has been offered by the Swiss scholar, Wolfram von den Steinen, together with an edition of the sequences of the St. Gall school.[25] What scholars in general have taken away from Notker with one hand they return with the other, for if not an originator he is conceded to be the leading agent in introducing the sequence into Germany and setting a standard for this type of poetry which included from Notker’s pen a notable group of sequences for the festivals of the whole year. His sequence for Pentecost is representative of the achievements of the German school.