noun (n)

• compatibility in opinion and action(noun.attribute)

  Synonym:
  harmoniousness
  

  source: wordnet30
• the structure of music with respect to the composition and progression of chords(noun.communication)

  Synonym:
  musical harmony
  

  source: wordnet30
• 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(noun.state)

  Synonym:
  concord, concordance
  

  source: wordnet30
• agreement of opinions(noun.communication)

  source: wordnet30
• an agreeable sound property(noun.attribute)

  Antonym:
  dissonance
  

  source: wordnet30
• The just adaptation of parts to each other, in any system or combination of things, or in things intended to form a connected whole; such an agreement between the different parts of a design or composition as to produce unity of effect; as, the harmony of the universe.(noun)

  source: webster1913