contrast- start very soft and become loud then soft again. this is used to give music life or “breath”
unity- have multiple parts singing in unison or at the same pitch and rhythm.
Balance- even 3 part harmony. very even and pretty same rhythm.
Emphasis- use a crescendo into a second interval between two parts. try your best to only use that on the exact word or phrase you want to have stick out.
you could also crescendo the phrase or word but that has less of an effect.
