Answer:

1. It is the simultaneous sounding of two or more pitches.

a. chord

b. fourth

c. harmony

d.ro do un of three tones

Harmony is the simultaneous sounding of two or more different tones. It can refer to the simultaneous intervals generated by polyphony, or to the chords (three or more tones sounded at the same time) or drone accompanying the melody.

I hope that helped