About Technique ? Sway
"Sway is the natural inclination of the whole body, including the legs from the ankles upwards, which is used on all normal turning figures." (Technical definition)
Sway has a vital part to play as one of the most important means by which a dancer is able to give 'expression' to four of the five Ballroom dances (Tango is the exception). Sway, as presented by a dancer with artistic feeling, is an art‑form in itself. It is also one of the charted elements of the Technique!
The artistic effect of the normal 'balancing' Sway that features in the Technique books lies (a) in the immaculate cleanliness of head‑to‑toes body line of the expert and (b) in the out‑of‑the perpendicular balanced angles of the body that can be achieved by the application of varying speeds into and through turns and curves.
Artistry also lies within (c) the skills needed to combine effectively the principles of Contra Body Movement and Sway in different types of simple and complex turning movements. These two elements of Technique are literally "Siamese twins it, the creating of visually effective artistic dancing; that is, CBM on the first step of a turning or curving figure is followed by Sway on the second and (usually) the third steps.
This rule should always be borne in mind when amalgamating figures into groups for competition purposes (or for Medal Tests).
Natural Balancing Sway (i.e. Banking on Turns and Curving Figures). The body‑swing dances use straight‑line Sway as a balancing force on turns (but not on pivots or spins during which the Man remains upright, except as in the Note below). Artistic effect comes from being able to maintain an immaculate line from head to toe while keeping perfect balance during the dancing of any type of acceptable movement or pose!
To give you a mental picture, this basic form of dynamic Sway is applied in a manner comparable to that of the skilled motor‑cyclist banking when making a turn.
To use another illustration, if an aircraft turning to a new direction is perfectly balanced, with the forces of turn (centripetal force) and bank (centrifugal force) being equal, although you might be able to see the ground through a window on one side and the sky through a window on the other side, you would still feel as though the aircraft were flying level.
A dancer swaying correctly would similarly be exhibiting perfect balance.
Because it is important, I will repeat for emphasis that the bodyline during this kind of balancing sway must be that of a straight line from head to toe. Any breaking of the line at the waist or hips on this kind of sway should be regarded as an error.
Notes: However, Standing Spins in Promenade Position might employ "arcing" Sway, where the upper body of both partners could be tilted in the direction of motion. It should also be noted that 'Picture' steps such as the family of Oversways, Lunges, Spanish Drags, etcetera, may legitimately use Sway lines, straight or arced, as they are used for effect not for balance.
Normal choreographic construction of the Standard dances, usually composed primarily of turns and curves to left and right, is such that the dynamic forces on turning movements should cause the male dancer to be leading the partnership almost continuously into straight‑line lateral Sways of angles of varying degrees from the vertical, the precise angle dependent on the relative body speed through each turn.
This, to remind you, is the type of Sway that is referred to in books on technique; the type of Sway that all professional candidates have had to study in order to gain their qualifications in Ballroom dancing as teachers and adjudicators. This is the lateral balancing Sway that is always used when the body is swinging through, for example, the second and third steps of Natural & Reverse Turns.
It is a categoric fact that Basic Sway cannot exist without body swing.
For a dance partnership, the angle of Sway required to maintain balance is dependent upon the speed of motion over the floor. The Swing/Sway equation is thus a variable factor. The faster that the body is moving through the turn or curve or the greater the amount of change of alignment, then the greater the angle of Sway needed to maintain equilibrium.
If the dancer is doing little more than walking to music, that is, if no body swing is being applied, then the sway needed to balance the body will be negligible or non‑existent.
But if, at the other extreme, speed of movement is built up, say, in a section of choreography culminating in a rapid acceleration into a Hover Cross in a corner, with the exit line being in the opposite direction; e.g. Diagonal to Center of new Line of Dance, then the balancing Sway on the third and fourth steps of the Hover Cross could be almost at the gravity defying angle of 45 degrees to the perpendicular. Such an entry into a Hover Cross, balanced with straight-line Sway, makes for a visually thrilling angle of bodyline but many competition dancers seem to be unaware of the impact they can make through dance effective Style 'pictures' such as this.
Dependent on the speed of movement and the degree of turn of any particular figure, the lateral angle from the perpendicular of most Sway lines in a dancer's choreography would lie somewhere between the two extremes cited above.
In ballroom dancing, for anyone who wishes to progress beyond the purely social aspect and develop dancing as an art form, the production of straight‑line sway is an essential skill.
This type of Sway was first introduced in the immediate postwar era. It is a supplement, not a replacement, to the straight‑line Sway of the Technique books.
It may be employed, for instance, in figures such as an anti‑clockwise Standing Spin in Promenade Position, where the Man has his weight centered on the pivoting Ball of his Left Foot while leading the Lady into a fast spin (or the alternative of a smoothly accelerating decelerating spin) around the centered leg, Both bodies may be arced in the direction of movement.
Arcing Sway is led by the male dancer, who by an additional stretch of the waist muscles on the one side of the body, leads his partner into a tilting (arcing) of their upper bodies to the side.
The introduction of Double Sway lines, first to one side and then the other, in variants on the popular Oversway or Lunge type movements, can look attractive when danced by expert professional or amateur couples. But many less expert dancers misguidedly fabricate a semblance of curved line sway, not by additional body stretch but by the unattractive option of collapsing, concertina‑wise, the waist muscles of the Sway side of the body. Even more undesirable is the practice of laterally tilting the arms to create an appearance of Broken Sway or, if dancing a double sided Sway movement, by a 'see‑sawing' of the arms.
Dancers need to be constantly reminded that all such Arcing Sway movements should be body, not arm, energized; that is, motivated by the waist muscles; the 'muscle cummerbund' control center of the body.
DanceSport enthusiasts should first learn and practice straight‑line Sway until it is fully and indelibly committed to muscle memory. Then and only then should they embark upon a similar mastery of the art of Arcing ‑ not broken ‑Sway.
There is another kind of postural Sway that is less acceptable from Men. This is the adoption by the male partner of the backbend type of Sway that is traditionally used by the Lady dancer to express elegant femininity; a curve of the body that might be extended by, the Lady during a Spin, Contra Check or other Picture Line. This is the female role.
Leave it to them!