How did Guillaume de Machaut give upper voices greater rhythmic independence?

In the 14th century, Guillaume de Machaut contributed to the development of counterpoint by increasing the rhythmic independence of the upper voice parts. Specifically, he sometimes displaced the upper voice by a beat or more in relation to the other parts of the composition.1

This technique allowed for greater rhythmic complexity, building upon the structural foundations of isorhythm—a practice where rhythmic patterns were systematically repeated—which Machaut utilized extensively in his motets and other polyphonic works.231