Poetry is a form of literary art in which language is used for its aesthetic and evocative qualities in addition to, or in lieu of, its apparent meaning. Poetry may be written independently, as discrete poems, or may occur in conjunction with other arts, as in poetic drama, hymns or lyrics.Poetry, and discussions of it, have a long history. Early attempts to define poetry, such as Aristotle's Poetics, focused on the uses of speech in rhetoric, drama, song and comedy. Later attempts concentrated on features such as repetition and rhyme, and emphasised the aesthetics which distinguish poetry from prose. From the mid-20th century, poetry has sometimes been more loosely defined as a fundamental creative act using language.Poetry often uses particular forms and conventions to expand the literal meaning of the words, or to evoke emotional or sensual responses. Devices such as assonance, alliteration, onomatopoeia and rhythm are sometimes used to achieve musical or incantatory effects. Poetry's use of ambiguity, symbolism, irony and other stylistic elements of poetic diction often leaves a poem open to multiple interpretations. Similarly, metaphor and simile create a resonance between otherwise disparate images—a layering of meanings, forming connections previously not perceived. Kindred forms of resonance may exist, between individual verses, in their patterns of rhyme or rhythm.Some forms of poetry are specific to particular cultures and genres, responding to the characteristics of the language in which the poet writes. While readers accustomed to identifying poetry with Dante, Goethe, Mickiewicz and Rumi may think of it as being written in rhyming lines and regular meter, there are traditions, such as those of Du Fu and Beowulf, that use other approaches to achieve rhythm and euphony. In today's globalized world, poets often borrow styles, techniques and forms from diverse cultures and languages.