Rhythm, controlled or measured flow of movement, either aural or visual, usually produced by an ordered arrangement of differing elements of the medium concerned. Rhythm is a basic feature of all the arts, particularly music, poetry, and dance; rhythm can also be detected in natural phenomena.

In music, rhythm in the general sense consists of everything pertaining to the forward movement of music in time (see Musical Rhythm). In dance, rhythm governs the movements of the body.

In prose writing, the rhythmic impulse prompts the balance of sentences and arrangement of words. Rhythm is a basic feature governing the structure of poetry, whether in the planned succession of long and short syllables, as in Greek and Latin poetry, or in the use of accent and meter, as in modern poetry (see Versification). Rhyme may also contribute to rhythmic effect in poetry. In the visual arts, objects or shapes may be juxtaposed to produce a rhythmic composition.

In nature, rhythm can be said to exist in the unending series of activities, such as sleeping and waking, feeding, and reproducing, that govern the existence of all living matter. Such activities often appear to be closely related to the rhythmic processes of geophysical phenomena, such as the ocean tides (see Tide), the solar day, the lunar month, and seasonal changes. See Calendar; Ecliptic.