_Ad matutinas laudes_ _Aeterne rerum conditor_ (In Old Hymnal) _Splendor paternae gloriae_ (In Old Hymnal) _Ales diei nuntius_ _Nox et tenebrae et nubila_ _Lux ecce surgit aurea_ _Aeterna caeli gloria_ _Aurora iam spargit polum_ _Ad completorium_ _Christe qui lux es et dies_ (In Old Hymnal; Mozarabic) _Te lucis ante terminum_ _Proprii de tempore_ _Ad cenam agni providi_ (In Old Hymnal) _Aurora lucis rutilat_ (In Old Hymnal) _De communi sanctorum_ _Martyr Dei qui unicum_ _Rex gloriose martyrum_ _Aeterna Christi munera_ (In Old Hymnal) _Sanctorum meritis inclita gaudia_ _Virginis proles opifexque_ _Iesu corona virginum_ _Summe confessor sacer_ CHAPTER FOUR The Ninth Century Revival: Sequences I. Origin The problem presented by the origin of the sequence is perhaps the most difficult of all those connected with the evolution of medieval hymnology. So far the available information on the subject has never been brought together in one place. To do so is a baffling task which has by no means been completed here nor is that which follows either exhaustive or conclusive. It is merely an attempt to trace the origin and early development as far as the evidence at hand makes it possible, at the same time referring the reader to those scholars who have investigated special topics in detail. The _alleluia_ of the mass is the starting-point of the sequence. Inherited from the synagogue and incorporated in the Byzantine rite, it was nevertheless brought independently to Rome. The extension of the final _a_ constituted a musical phrase, called a _iubilus_ or _iubilatio_. This elaborated _alleluia_ with _iubilus_ is Gregorian.[1] It became necessary for the sake of breathing, to divide the extended _iubilus_ into musical phrases, each a _sequentia_ and the whole _sequentiae_. Some _iubili_ however, remained single while others were sung by two choirs with a repetition of phrases. The next step was the composition of a text for some of the _iubili_, which text was written below the musical notation. Finally a text was supplied for every such melody, which resulted in the _sequentia cum prosa_.[2]