Isorhythm

A medieval principal of construction which was used most often in motets. This construction is based on a repeating rhythmic pattern in one or more of the voices. a technique for musical organization used during the fourteenth and early fifteenth centuries in which the tenor repeats a certain pattern of pitches (the "color") and a certain rhythmic pattern (the "talea"). The color and talea may be different lengths. Used commonly in the motet; also used in some mass settings, for example in the Messe de Notre Dame by Guillaume de Machaut.