In spite of the evidence which would make the sequence a native musical product of western Europe, the theory of Greek origin is still persistently held by certain scholars. For that reason it must be considered in greater detail. Gregory’s adoption of Greek novelties forms the starting point of this theory, while Charlemagne’s well-known enthusiasm for Greek innovations carries its proponents still further. The fact that the original Greek melodies which are assumed to have been used in the west, have never been produced in evidence, is not a proof of their non-existence. An extensive study of certain sequence melodies has been made in order to determine whether they are modeled upon Greek originals, since the Greek names for these melodies and features of notation point to such an origin.[12] But such names are secondary, the original and natural name being the first phrase of the Latin words accompanying the melodies and the Greek word a suggested title. A Greek melody, called _Organa_, for instance, might be assumed to retain its name in Latin. The opposite is the case for the name _Filia matris_ is original and _Organa_ the suggested title. Regarding the argument from notation it is a matter of common knowledge that the _neume_ is native to Greek-speaking lands and may have existed as early as the sixth century.[13] _Neumes_ took firm root at St. Gall, the great German center for the propagation of the sequence, so much so, that they persisted until the twelfth century even after the invention of the staff and in the interval were spread by teaching. Moreover, _neumes_ were written in the manner of the eastern church, _i.e._ in a straight line, not at different levels to indicate pitch.[14] It is unfortunate that the dearth of manuscripts showing _neumes_ makes a gap in the evidence just where support is most needed, for the earliest musical manuscripts with this notation date from the ninth century;[15] but the assumption in favor of Greek originals is at least strong enough to forbid its being ignored. 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.