The word cadence has its own lovely cadence — rhythm of sound as it's spoken.
Cadence has come to mean "the rhythm of sounds" from its root cadere which means "to fall." Originally designating falling tones especially at the end of lines of music or poetry, cadence broadened to mean the rhythms of the tones and sometimes even the rhythm of sounds in general. Think of the cadence of the marching band at a football game or the cadence of the crickets on a warm spring night. You can remember the "fall" idea by thinking of one of the only words that contains it — decadence — which has the prefix de- at the front to mean down, or downfall.