Answer:
consonance
Step-by-step explanation:
In music theory, consonance refers to the quality of consecutive or simultaneos sound that fit together in an agreeable, pleasing manner.
Consonant chords will naturally turn into a "sounding good" sensation, often referred as well as "happy" sounds like middle C and G.
They make up a perfect fifth.
The perfect fifth and the perfect octave form perfect consonances. ...
The major third and sixth, referred as minor third and sixth, are imperfect consonances.
The opposite are the dissonant chords, which often will give a turn in the direction of the feeling of the piece, and they are also sometimes simply viewed as "sad" notes.