Dance and rhythm

Rhythm and dance are deeply linked in history and practice. The American dancer Ted Shawn wrote; "The conception of rhythm which underlies all studies of the dance is something about which we could talk forever, and still not finish." A musical rhythm requires two main elements; first, a regularly-repeating pulse (also called the "beat" or "tactus") that establishes the tempo and, second, a pattern of accents and rests that establishes the character of the metre or basic rhythmic pattern. The basic pulse is roughly equal in duration to a simple step or gesture.

Dances generally have a characteristic tempo and rhythmic pattern. The tango, for example, is usually danced in 2
₄ time at approximately 66 beats per minute. The basic slow step, called a "slow", lasts for one beat, so that a full "right–left" step is equal to one 2
₄ measure. The basic forward and backward walk of the dance is so counted – "slow-slow" – while many additional figures are counted "slow – quick-quick.

Just as musical rhythms are defined by a pattern of strong and weak beats, so repetitive body movements often depends on alternating "strong" and "weak" muscular movements. Given this alternation of left-right, of forward-backward and rise-fall, along with the bilateral symmetry of the human body, it is natural that many dances and much music are in duple and quadruple meter. However, since some such movements require more time in one phase than the other – such as the longer time required to lift a hammer than to strike – some dance rhythms fall equally naturally into triple metre. Occasionally, as in the folk dances of the Balkans, dance traditions depend heavily on more complex rhythms. Further, complex dances composed of a fixed sequence of steps always require phrases and melodies of a certain fixed length to accompany that sequence.

The very act of dancing, the steps themselves, generate an "initial skeleton of rhythmic beats" that must have preceded any separate musical accompaniment, while dance itself, as much as music, requires time-keeping just as utilitarian repetitive movements such as walking, hauling and digging take on, as they become refined, something of the quality of dance.

Musical accompaniment therefore arose in the earliest dance, so that ancient Egyptians attributed the origin of the dance to the divine Athotus, who was said to have observed that music accompanying religious rituals caused participants to move rhythmically and to have brought these movements into proportional measure. The same idea, that dance arises from musical rhythm, is still found in renaissance Europe in the works of the dancing master Guglielmo Ebreo da Pesaro who speaks of dance as a physical movement that arises from and expresses inward, spiritual motion agreeing with the "measures and perfect concords of harmony" that fall upon the human ear, while, earlier, Mechthild of Magdeburg, seizing upon dance as a symbol of the holy life foreshadowed in Jesus' saying "I have piped and ye have not danced", writes;

I can not dance unless thou leadest. If thou wouldst have me spring aloft, sing thou and I will spring, into love and from love to knowledge and from knowledge to ecstasy above all human sense

Thoinot Arbeau's celebrated 16th century dance-treatise Orchésographie, indeed, begins with definitions of over eighty distinct drum-rhythms.

As has been shown above, dance has been represented through the ages as having emerged as a response to music yet, as Lincoln Kirstein implied, it is at least as likely that primitive music arose from dance. Shawn concurs, stating that dance "was the first art of the human race, and the matrix out of which all other arts grew" and that even the "metre in our poetry today is a result of the accents necessitated by body movement, as the dancing and reciting were performed simultaneously" – an assertion somewhat supported by the common use of the term "foot" to describe the fundamental rhythmic units of poetry.

Scholes, not a dancer but a musician, offers support for this view, stating that the steady measures of music, of two, three or four beats to the bar, its equal and balanced phrases, regular cadences, contrasts and repetitions, may all be attributed to the "incalculable" influence of dance upon music.

Émile Jaques-Dalcroze, primarily a musician and teacher, relates how a study of the physical movements of pianists led him "to the discovery that musical sensations of a rhythmic nature call for the muscular and nervous response of the whole organism", to develop "a special training designed to regulate nervous reactions and effect a co-ordination of muscles and nerves" and ultimately to seek the connections between "the art of music and the art of dance", which he formulated into his system of eurhythmics. He concluded that "musical rhythm is only the transposition into sound of movements and dynamisms spontaneously and involuntarily expressing emotion".

Hence, though doubtless, as Shawn asserts, "it is quite possible to develop the dance without music and... music is perfectly capable of standing on its own feet without any assistance from the dance", nevertheless the "two arts will always be related and the relationship can be profitable both to the dance and to music", the precedence of one art over the other being a moot point. The common ballad measures of hymns and folk-songs takes their name from dance, as does the carol, originally a circle dance. Many purely musical pieces have been named "waltz" or "minuet", for example, while many concert dances have been produced that are based upon abstract musical pieces, such as 2 and 3 Part Inventions, Adams Violin Concerto and Andantino. Similarly, poems are often structured and named after dances or musical works, while dance and music have both drawn their conception of "measure" or "metre" from poetry.

Shawn quotes with approval the statement of Dalcroze that, while the art of musical rhythm consists in differentiating and combining time durations, pauses and accents "according to physiological law", that of "plastic rhythm" (i.e. dance) "is to designate movement in space, to interpret long time-values by slow movements and short ones by quick movements, regulate pauses by their divers successions and express sound accentuations in their multiple nuances by additions of bodily weight, by means of muscular innervations".

Shawn nevertheless points out that the system of musical time is a "man-made, artificial thing.... a manufactured tool, whereas rhythm is something that has always existed and depends on man not at all", being "the continuous flowing time which our human minds cut up into convenient units", suggesting that music might be revivified by a return to the values and the time-perception of dancing.

The early-20th-century American dancer Helen Moller stated simply that "it is rhythm and form more than harmony and color which, from the beginning, has bound music, poetry and dancing together in a union that is indissoluble."