What was the opposite of harmony and used disagreeable sounds?

The opposite of harmony, using disagreeable sounds, is called dissonance.

Here's why:

* Harmony is a pleasing combination of sounds, usually created by notes that sound good together.

* Dissonance is a combination of sounds that create a sense of tension or unpleasantness. It often involves notes that clash or sound "wrong" together.

In music, both harmony and dissonance are essential elements. Dissonance creates tension that needs to be resolved, leading to a sense of satisfaction when the harmony returns.