In the military, a CDC is a Career Development Course. It's like a series of home study books to help you in your career specialty, and advance in rank. gromit801 Â· 1 decade ago
Aleatoric music, also known as aleatory music, is music with a random element. Chance elements within a piece can be used for composition, as well as for live performance. When a piece is being composed, random elements can be used to influence the outcome of a final musical piece.
Prehistoric music (previously primitive music) is a term in the history of music for all music produced in preliterate cultures (prehistory), beginning somewhere in very late geological history. Prehistoric music is followed by ancient music in different parts of the world, but still exists in isolated areas. However, it is more common to refer to the prehistoric music which still survives as folk, indigenous or traditional music. Prehistoric music is studied alongside other periods within music archaeology.