The study is devoted to the problem of motion analysis and centers on 20th century social dancing and dance theatre. The main focus is on the motorics of the body-in-motion. Analytic observation and description (by means of a newly developed system for recording movement) chart the phenomena studied in terms of the way they form 'motion-texts'. The usefulness of this system is evidenced not only in comparison with traditional description and notation techniques but more especially in the confrontation of popular 20th century dance forms (from tango to twist) with works of dance theatre from the period between 1910 and 1965. The analysis identifies period-specific patterns of motoric identity that owe nothing to traditional concepts of style or genre. The avenues thus opened up would also repay exploration for their potential contribution to a historical study of bodily movement in a broader theatrical and cultural ambit.