The creation and transmission of the earliest Gregorian chant did not happen within the framework of the eight Gregorian modes. The earliest written sources (ninth century) do not assign modes to the chants. Notated antiphonaries from the end of the tenth century begin to contain marginal indications of mode. The question is not why Gregorian chant adopted the octoechos: it is about why it accepted a sense of finality in chant, a sense of a resting-place, which is withheld. It is significant both that Gregorian chant alone of the Latin repertories came under the influence of the octoechos, and that body of Gregorian chant contains much more differentiation of the final by leap than other Latin repertories. If we were to abandon a rigorous definition of modality and instead look at what a modal “system” might have done for the Carolingians, it might have provided a signpost to the final cadential degree.