RHYTHM

in poetry, the patterned recurrence, within a certain range of regularity, of specific language features, usually features of sound. Although difficult to define, rhythm is readily discriminated by the ear and the mind, having as it does a physiological basis. It is universally agreed to involve qualities of movement, repetition, and pattern and to arise from the poem's nature as a temporal structure. Rhythm, by any definition, is essential to poetry; prose may be said to exhibit rhythm but in a much less highly organized sense. The presence of rhythmic patterns heightens emotional response and often affords the reader a sense of balance. Metre (q.v.), although often equated with rhythm, is perhaps more accurately described as one method of organizing a poem's rhythm. Unlike rhythm, metre is not a requisite of poetry; it is, rather, an abstract organization of elements of stress, duration, or number of syllables per line into a specific formal pattern. The interaction of a given metrical pattern with any other aspect of sound in a poem produces a tension, or counterpoint, that creates the rhythm of metrically based poetry. Compared with the wide variety of metrical schemes, the types of metrically related rhythms are few. Duple rhythm occurs in lines composed in two-syllable feet, as in Shakespeare's line, In metrical schemes based on three-syllable feet, the rhythm is triple: Rising rhythm results when the stress falls on the last syllable of each foot in a line: The reverse of this is falling rhythm: Running, or common, rhythm occurs in metres in which stressed and unstressed syllables alternate (duple rhythm, rising or falling). Gerard Manley Hopkins, in reaction against traditional metres, coined the term sprung rhythm (q.v.) to apply to verse wherein the line is measured by the number of speech-stressed syllables, the number of unstressed syllables being indeterminate. The rhythms of free verse (q.v.) derive from the systematic repetition of language elements other than metrical stress patterns. Differentiation between the rhythmical basis of free verse and that of metrical verse involves a relative, rather than an absolute, distinction regarding the range of language features considered and the extent to which they are patterned. Since metrical verse is principally concerned with the distribution of relative stress values, it does not account for the significance of other linguistic features that may contribute to rhythmic effect. In free verse, rhythm most commonly arises from the arrangement of linguistic elements into patterns that more nearly approximate the natural cadence of speech and that give symmetry to the verse. The rhythmical resources available to free verse include syntactical patterning; systematic repetition of sound, words, phrases, and lines; and the relative value of temporal junctures occasioned by caesura (a marked pause in the middle of a line), line length, and other determinants of pace. Some authorities recognize in the highly organized patterning of imagery a further source of poetic rhythm. The following lines from Walt Whitman's Song of Myself illustrate many of these rhythmical devices: Twenty-eight young men bathe by the shore, Twenty-eight young men and all so friendly; Twenty-eight years of womanly life and all so lonesome. She owns the fine house by the rise of the bank, She hides, handsome and richly drest aft the blinds of the window. The rhythms that are characteristic of particular poets are sometimes ascribed to units of breath, as in the essay Projective Verse (1950) by the poet and critic Charles Olsen: And the line comes (I swear it) from the breath, from the breathing of the man who writes, at the moment that he writes . . . . in music, element of time. Since music unfolds in time, it might seem that rhythm is its most important aspect, but the rhythmic elementthe placement of sounds in timecannot be divorced from the nature of the sounds themselves; for instance, a regular rhythm of one sound per second will produce a quite different effect depending on whether the sounds are drum strokes, notes on a piano, or orchestral chords. By extension it becomes clear that rhythm is not just a matter of timing; it depends also on accentuation, interval, harmony, and tone colour. The foundation of rhythm in most music is simple; it is the regular beat. Indeed, in everyday language the word rhythm often refers to this kind of pulsation; one speaks of the rhythm section in a light orchestral arrangement, or of musicians having a sense of rhythm when emphatic regular accents are the result. A prominent beat tends, too, to be the most important rhythmic feature in music originating in the dance, whether it be a mazurka, a rock number, or an African drum solo. The organization of beats is the province of metre. In Western music the most common metres are duple, with two beats to the bar, and triple, with three beats to the bar, plus their various compounds, such as quadruple, with two units of two beats (a traditional marching metre), and sextuple, with two units of three beats. Normally a piece will be a succession of bars having essentially the same metre, though of course the beats may be combined or divided differently in different bars, and all sorts of variations are possible. The origins of rhythm in Western music are a matter of dispute. Some authorities maintain that plainsong was performed with a decisive metre, while others hold that it was delivered in an irregular manner, as in speech. Musicians had certainly developed a notation for different kinds of metre by the 12th century, however, and during the 14th century the notation of rhythm reached a peak of complexity unequaled until the 1950s. This refinement could not, though, be sustained once composers began giving more thought to harmony, as happened during the Renaissance, and rhythm regained its foundations in simplicity and regularity. What happened during the 17th century was a division into two varieties of rhythm, one based on repeating pattern in the manner of dance, the other based on the freer rhythms of speech and to be found most usually in music for solo voice; this division is reflected in the distinction in opera between aria and recitative. Meanwhile, the clarity of design in the former kind of music had much to do with the rhythmic achievements of Joseph Haydn, Wolfgang Amadeus Mozart, and Ludwig van Beethoven, who were able to work with great subtlety at several different levels within the transparent outline of even (as opposed to odd) bars and even groupings of them, usually into phrases of four or eight bars. The 19th century saw an erosion of this metrical system through an abundance of cross rhythms, subdivisions, and irregularities, to the extent that many composers in the 20th century discarded metre along with the system of major and minor keys. In some cases the primitive pulsation has been brought once more to the surface, as in Igor Stravinsky's Rite of Spring. In others all traces of rhythmic pattern have been abandoned. in music, the placement of sounds in time. In its most general sense rhythm (Greek rhythmos, derived from rhein, to flow) is an ordered alternation of contrasting elements. The notion of rhythm also occurs in other arts (e.g., poetry, painting, sculpture, and architecture) as well as in nature (e.g., biological rhythms). Attempts to define rhythm in music have produced much disagreement, partly because rhythm has often been identified with one or more of its constituent, but not wholly separate, elements, such as accent, metre, and tempo. As in the closely related subjects of verse and metre, opinions differ widely, at least among poets and linguists, on the nature and movement of rhythm. Theories requiring periodicity as the sine qua non of rhythm are opposed by theories that include in it even nonrecurrent configurations of movement, as in prose or plainchant. Additional reading Curt Sachs, Rhythm and Tempo (1953), the most comprehensive work on rhythm in music, ranges over many non-Western cultures as well as over the successive periods of Western musical history. Detailed rhythmical analyses of Western music since the 17th century appear in Grosvenor W. Cooper and Leonard B. Meyer, The Rhythmic Structure of Music (1960). Studies of special periods are available in Charles F. Abdy Williams, The Aristoxenian Theory of Musical Rhythm (1911); W.F. Jackson Knight, St. Augustine's De Musica: A Synopsis (1949); William G. Waite, The Rhythm of Twelfth-Century Polyphony, Its Theory and Practice (1954); Philip F. Radcliffe, The Relation of Rhythm and Tonality in the Sixteenth Century, Proc. R. Musical Assn., 57:7397 (1931); and Henry D. Cowell, New Musical Resources (1930, reprinted 1969). Particular applications of rhythm have been studied in Charles F. Abdy Williams, The Rhythm of Song (1925); and William Thomson, The Rhythm of Speech (1923). Aesthetic aspects are considered in Margaret Glyn, The Rhythmic Conception of Music (1907); and Mathis Lussy, Le Rythme musical, 3rd ed. rev. (1897; abridged Eng. trans., A Short Treatise on Musical Rhythm, 1909). mile Jaques-Dalcroze, Le Rythme, la musique et l'ducation (1920; Eng. trans., Rhythm, Music and Education, 1921), is the pioneer work in its aspect of the field; musical rhythm has been put in wider perspective by Elsie Fogerty, Rhythm (1937).