Chailley, École musicale, p. 267 

Chailley offers a melodic reconstruction for the first two strophes in a rhythmically neutral format i.e. using noteheads without stems. Suggestions of phrasing are nevertheless made through placing barlines at the end of lines and ticks at the caesura. The reconstruction is plausible, although the use of B as a lower boundary tone in the opening two lines of each strophe is surprising within an otherwise standard first-mode melody.

There are no similarities between the two notations in melodic profile, organization within the strophe or melodic return beyond the first strophe. Other observations may nevertheless be made about transmission since there is a striking similarity between the melodic profiles recorded for Tertio in flore in Napoli IV. G. 68 and Fuit Domini in Paris lat. 1154: for a commentary on this relation, see the entry for Fuit Domini. What is pertinent here is that the melodic profile recorded in Napoli IV. G. 68 appears to be one applied to a particular text form (4 x 8p+7pp) rather than a particular text. This behaviour serves to associate the melody with the shared melodies for similar poetic forms common to the hymn repertory. The melody recorded in Paris lat. 1121 takes a different genre as its point of departure, namely the sequence. The regularization of accentuation and syllable count in sequence texts through the early middle ages, with the result that the new sequence texts in the eleventh century are predominantly in regular verse forms, appears to have motivated a melodic treatment of Tertio in flore as a sequence. In other words, the accentual trochaic septenarius lines of Tertio in flore were regarded as suited to a melodic treatment as a sequence under the new stylistics. The two different practices for the melodic projection of Tertio in flore observed here may be broadly categorised as belonging to Old and New Song styles respectively. Rather than understanding the two notations as residues of a process of transmission, a more convincing way of interpreting the surviving notations is as records of distinct ways of responding to a single text through melody.