Dance is an art form that involves movement of the body, often to the accompaniment of music or song, or movement of objects under direct or indirect control of the artist.
The term dance is also used to describe various specific forms of movement used by organisms during mating, aggression, communication, or other specific kinds of behaviour. Generally these so-called dance movements involve groups of movements which do not occur in normal activity. These dance-like behaviours, also known as 'fixed action patterns', are distinguished by repetition, exaggeration or difficulty.
Many species of Terragen life, and xenobiota from many worlds, perform such patterns of behaviour under a wide range of circumstances; even evolved feral robots found on botworlds such as Stanislaw, and virtual entities (especially sims and a-lifes) have been observed to develop similar patterns of movement for particular purposes. Artistic forms of dance as performed by sophonts can be regarded as an extension of this form of behaviour by sophont beings, for entertainment and ritualistic purposes. As among humans on Old Earth, dance may be participatory and social or a virtuoso performance, and may be part of a ceremony or a competition, or simply for personal amusement. The movements may be abstract or may encode specific meanings and stories, though if a clade uses dance-like motions as a primary mode of communication it is generally considered as a form of language rather than art per se. Dance styles exploded in diversity during the Interplanetary Age, with the addition of new capabilities and environments and new clades of sophonts.
The most extreme forms of dance are not only artistically pleasing but also strenuous and even dangerous. Certainly this is true in a gravity well or under acceleration, especially in high-g circumstances or in small rapidly rotating habs where coriolis effects are large, but it is equally true of certain types of microgravity or low gravity dance which involve long and rapid trajectories and powerful impacts and may cause injuries or fatalities among dancers and audience alike.