A hinge is a half of a trade. Any two adjacent couples or dancers who can trade can also hinge. 

(a) COUPLES HINGE: Starting formation: line or two-faced line. Working as a unit, each couple does half of a couples trade to end in a two-faced line at right angles to the original line. 

(b) SINGLE HINGE: Starting formation: mini wave. Dancers do half of a trade with each other to end in a mini wave at right angles to the original mini wave.

Styling: Couples use couple handhold and styling similar to wheel and deal. Single hinge use hands up position. 

Timing: Couples hinge, 3 steps; single hinge, 2 steps.