Answer:

The unitary song uses the same melody repeated over and over, with different text for each repetition. The song may include a chorus or a refrain. In the refrain, the same text is sung to the same melody for each repetition

Example:

Twinkle, twinkle, little star

How I wonder what you are

Up above the world so high

Like a diamond in the sky

Twinkle, twinkle, little star

How I wonder what you are

etc.