Language itself is good at communicating information, but it is deficient in conveying affective states to others. Humans are able to accomplish a great deal of affective communication with tropic expression, such as metaphor, but even these structures lack immediacy. When humans really want to express interpersonal affect, language often breaks down. Most human societies find orgiastic behavior unpalatable or impractical. Auditory and visual channels for communication have the advantage of being able to encompass and affect large numbers of individuals without the need to touch, smell or taste every other person in the group.
Normal language is of course primarily conveyed through auditory and visual channels.
It is then not surprising that forms of communication conveying affect in an immediate manner have language as a component, but provide significant enhancements from other dimensions of communication. Singing is only one of a number of forms of behavior that qualify as enhanced communication. Chant can be done by an individual, but it is most often a group behavior that strengthens solidarity among participants through shared vocal activity. The propositional content of chant is secondary to its acoustic properties and the fact that it is a shared activity. Chant is often a way of inducing broader shared experience in the form of trance or deep meditative states, as seen in the practices of religious orders.