harmony

(noun) compatibility in opinion and action. Synonyms: harmoniousness.

(noun) the structure of music with respect to the composition and progression of chords. Synonyms: musical harmony.

(noun) a harmonious state of things in general and of their properties (as of colors and sounds); congruity of parts with one another and with the whole. Synonyms: concord, concordance.

(noun) agreement of opinions. Synonyms: concord, concordance.

(noun) an agreeable sound property.