rhythm.
Merriam-Webster Online Dictionary
cadence (noun)1.
a) a rhythmic sequence or flow of sounds in language
b) the beat, time, or measure of rhythmical motion or activity
2.
a) a falling inflection of the voice
b) a concluding and usually falling strain , specifically a musical chord sequence moving to a harmonic close or point of rest and giving the sense of harmonic completion
3.
the modulated and rhythmic recurrence of a sound especially in nature