Study of the elements of language, especially metre, that contribute to rhythmic and acoustic effects in poetry. The basis of traditional prosody in English is the classification of verse according to the syllable stress of its lines. Effects such as rhyme scheme, alliteration, and assonance further influence a poem's sound meaning. Nonmetrical prosodic study is sometimes applied to modern poetry, and visual prosody is used when verse is shaped by its typographical arrangement. Prosody also involves examining the subtleties of a poem's rhythm, its flow, the historical period to which it belongs, the poetic genre, and the poet's individual style.