Oral-formulaic composition
Oral-formulaic composition is a theory that originated in the scholarly study of epic poetry and developed in the second quarter of the twentieth century. It seeks to explain two related issues: The key idea of the theory is that poets have a store of formulae (a formula being 'an expression that is regularly used, under the same metrical conditions, to express a particular essential idea') and that by linking the formulae in conventionalised ways, poets can rapidly compose verse. Antoine Meillet expressed the idea in 1923, thus: In the hands of Meillet's student Milman Parry  (1902-1935), and subsequently the latter's student Albert Lord (1912-1991), the approach transformed the study of ancient and medieval poetry and of oral poetry generally. The main exponent and developer of their approaches was John Miles Foley (1947-2012). Homeric verse. In Homeric verse, a phrase like "eos rhododaktylos" ("rosy fingered dawn") or "oinops pontos" ("winedark sea") occupies a certain metrical pattern that fits, in modular fashion, into the six-colon Greek hexameter, which aids the "aoidos" or bard in extemporaneous composition. (The Illiad and The Odyssey both use dactylic hexameter verse form, where every line contains six  groups of syllables.) Moreover, such phrases would be subject to internal substitutions and adaptations, permitting flexibility in response to narrative and grammatical needs: "podas okus axilleus" ("swift footed Achilles") is metrically equivalent to "koruthaiolos ektor" ("glancing-helmed Hector"). Formulas can also be combined into "type-scenes", longer, conventionalised depictions of generic actions in epic like the steps taken to arm oneself or to prepare a ship for sea. Work of Parry and successors. Oral-formulaic theory was originally developed, principally by Parry in the 1920s, to explain how the Homeric epics could have been passed down through many generations purely  through word of mouth and why its formulas appeared as they did. His work was influential in the field of Homeric scholarship and changed the discourse on the oral theory and the Homeric Question. The "locus classicus" for oral-formulaic poetry, however, was established by the work of Parry and his student Lord, not on oral recitation of Homer (which no longer was practiced), but on the (similar) Serbian oral epic poetry of what was then of Yugoslavia, where oral-formulaic composition could be observed and recorded ethnographically. Formulaic variation is apparent, for example, in the following lines: Lord, and  more prominently Francis Peabody Magoun, also applied the theory to Old English poetry (principally "Beowulf") in which formulaic variation such as the following is prominent: Magoun thought that formulaic poetry was necessarily oral in origin. That sparked a major and ongoing debate over the extent to which Old English poetry, which survives only in written form, should be seen as, in some sense, oral poetry. The oral-formulaic theory of composition has now been applied to a wide variety of languages and works. A provocative new application of oral-formulaic theory is its use in explaining the origin of at  least some parts of the Quran. Oral-Formulaic theory has also been applied to early Japanese works. The oral-formulaic theory has also been applied to the Olonko epic of the Sakha people of Siberia. Precursors of Parry. Before Parry, at least two other folklorists also noted the use of formulas among the epic tale singers of Yugoslavian (known as "guslars"), (something acknowledged by Parry):