Durations, and their beginnings and endings, may be described as long, short, or taking a specific amount of time. Often duration is described according to terms borrowed from descriptions of pitch. As such, the duration complement is the amount of different durations used, the duration scale is an ordering (scale) of those durations from shortest to longest, the duration range is the difference in length between the shortest and longest, and the duration hierarchy is an ordering of those durations based on frequency of use (DeLone et al. (Eds.), 1975, chap. 3).
Durational patterns are the foreground details projected against a background metric structure, which includes meter, tempo, and all rhythmic aspects which produce temporal regularity or structure. Duration patterns may be divided into rhythmic units and rhythmic gestures (DeLone et al. (Eds.), 1975, chap. 3). However, they may also be described using terms borrowed from the metrical feet of poetry: iamb (weak-strong), anapest (weak-weak-strong), trochee (strong-weak), dactyl (strong-weak-weak), and amphibrach (weak-strong-weak), which may overlap to explain ambiguity (Cooper and Meyer, 1960).
A Time At Which a Scale Is Created in the measurement of time and space. Also See Motivation8888