Written recording of dance movements.
The earliest notation, in the late 15th century, consisted of letter-symbols. Several attempts were made in later centuries to describe dance steps, but no unified system combined both rhythm and steps until the 1920s, when Rudolf Laban devised his system of Labanotation. In the 1950s, the competing system of Benesh notation, or "choreology," devised by Rudolf and Joan Benesh, came into use.