Modern western square dance dance, like traditional square dance, is directed by a "caller". In modern western square dance the caller strings together a sequence of individual "square dance calls" to make a figure or sequence. These calls are the building blocks of the choreography that is danced by the individuals – square dancers – in the squares. There are eight people (four pairs of males and females, traditionally) in each square; at a dance there may be many squares. Generally speaking, each of these squares dances independently of each other, with the exception of specialty or "gimmick" dances, where there might be some
Challenge square dance with more than 400 calls. C4 dancers typically know at least 700 calls. Challenge square dancing not only involves knowing many more calls, but is typified by the extensive use of Concepts, abstract and physical formations, "Phantom" dancers, and call deconstruction (such as Fractionalization). Some square dance calls are more complex than others, involving more series of actions and more abstract identifications of whom to do the action with. Challenge lists include more of these complex calls, but none are by themselves more complex than calls at the Advanced level. Much of Challenge dancing uses basic calls (such as "Right