The simplest model for explaining the transmission of the melody reconstructed from Paris lat. 8318 would be as follows:
Sapphic hymn melody (Monumenta monodica I, 107)
Pseudo-sapphic melody for Ad caeli clara (Paris lat. 8318, str. 2)
Pseudo-sapphic melody for Quis infelici (Vatican lat. 3797)
What is striking about this suggestion, however bare in outline, is that it mirrors the stages envisaged for the creation of the text of Ad caeli clara by Norberg i.e. the direct imitation of a Sapphic hymn by Eugenius of Toledo in Paulinus’ Ad caeli clara, followed by imitations of the pseudosapphic form of Ad caeli clara. Questions inevitably remain about every aspect of the process of melodic creation and transmission, the most tantalising of which is whether the hymn composed by Eugenius was sung to the widespread Sapphic melody thus opening up the possibility that melodic and textual imitation and transmission occurred alongside each other.
The similarity between the melody recorded for the second strophe in Paris lat. 8318 and the melody for Petrus Damiani’s Quis infelici in an
eleventh-century Italian manuscript raises the further question of whether the melody recorded in Paris lat. 8318 was known in Italy before its transmission to the North. This question cannot be answered definitively, but the similar later recording of a melody for Mecum Timavi in an Italian source that is found earlier in French sources (see the entry for Mecum Timavi) lends weight to the notion that certain melodies remained relatively stable in transmission and might have been known in Italy before transmission to France. It may additionally be noted that the same halfline pattern of repetition in the melody observed in Paris lat. 1154 and Paris lat. 8318, str. 1 is found for Gloriam Deo as notated in both Paris lat. 1154 and Roma, Biblioteca Angelica 123. It is therefore possible that a melody using this pattern of repetition (ab cb cd e) for the pseudo-sapphic strophe was also known in Italy before transmission north. All the melodies for Ad caeli clara are notated in West Frankish sources. The hand that added the text of Ad caeli clara is consistent with the midninth century Loire origin ascribed to the manuscript by Bischoff and a Loire provenance is possible given the characteristics of the notation. The Lotharingian notation in Bern 455 was in all probability added when the manuscript reached Laon, while the notation in Paris lat. 1154 was most likely added in Aquitaine. The evidence from notated manuscripts is thus that the poem was sung widely in West Francia at least during the tenth century. Notations were only added to Ad caeli clara in verse collections, but a wider sung dissemination may be assumed on the basis of the inclusion
of the poem among hymns in three unnotated manuscripts: Karslruhe, Badische Landesbibliothek Aug. CXCV 36, München, Bayerische
Staatsbibliothek Clm 27305 and Vatican Reg. lat. 334. In München 27305, the rubric Ymnus omnibus horis canendus points to the
singing of Ad caeli clara as an Office hymn. The fact that Ad caeli clara does not appear in hymnals nevertheless suggests that it was not routinely used in this way. The inclusion of Ad caeli clara alongside collects (München 27305), prayers (Vatican Reg. lat. 334) and penitential material (Karlsruhe 36) suggests instead a more occasional and devotional use.