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 process by which oral poets improvise poetry
- the reasons for orally improvised poetry (or written poetry deriving from traditions of oral improvisation) having the characteristics that it does
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: