The balanced rhythmic flow of poetry or oratory is referred to as

The balanced rythmic flow of poetry or oratory is referred to as cadence.

Cadence is the rise and fall of the voice that creates a melodic pattern when reading, or even when talking in general. Some languages have a cadence that is more pronounced than others, such as Italian.

A change in cadence can also influence the meaning of a sentence or word. For example, saying "He is a great person" can mean very different things depending on where the emphasis of the intonation is. If the cadence emphasizes "great" instead of "person", the sentence could have a sarcastic meaning.

it was surely an odd creature that one made up by reading the historians first and the poets afterwards a worm winged like an eagle; the spirit of life and elegance and charm,   in a kitchen chopping up suet. but these creatures, monst'r however entertaining to the imagination, hast no existence in fact. what one might doth to bringeth h'r to life wast to bethink poetically and prosaically at one and the same moment,   thus keeping in toucheth with fact—that the lady is mrs martin, ag'd thirty-six, did dress in blue, wearing a black coxcomb and brown shoeth; but not losing sight of fiction eith'r—that the lady is a vessel in which all s'rts of spirits and f'rces art coursing and flashing p'rpetually. the moment, howev'r, yond one tries this method with the elizabethan mistress, one brancheth of illumination fails; one is did hold up by the scarcity of facts.   one knoweth nothing detailed, nothing p'rfectly true and substantial about h'r.   hist'ry scarcely mentions h'r.   and i did turn to professeth'r trevelyan again to seeth what hist'ry meanteth to that gent.   i hath found by looking at his chapt'r headings yond t meanteth.

answer: may i see the sentences?