harmony vs unity

harmony

noun
  • Agreement or accord. 

  • A literary work which brings together or arranges systematically parallel passages of historians respecting the same events, and shows their agreement or consistency. 

  • A pleasing combination of elements, or arrangement of sounds. 

  • The relationship between two distinct musical pitches (musical pitches being frequencies of vibration which produce audible sound) played simultaneously. 

  • The academic study of chords. 

  • Two or more notes played simultaneously to produce a chord. 

unity

noun
  • Agreement; harmony. 

  • Any of the three classical rules of drama: unity of action (nothing should be admitted not directly relevant to the development of the plot), unity of place (the scenes should be set in the same place), and unity of time (all the events should be such as might happen within a single day). 

  • The peculiar characteristics of an estate held by several in joint tenancy. 

  • The form of consensus in a Quaker meeting for business which signals that a decision has been reached. In order to achieve unity, everyone who does not agree with the decision must explicitly stand aside, possibly being recorded in the minutes as doing so. 

  • A single undivided thing, seen as complete in itself. 

  • Oneness; the state or fact of being one undivided entity. 

  • The number 1 or any element of a set or field that behaves under a given operation as the number 1 behaves under multiplication. 

How often have the words harmony and unity occurred in a corpus of books? (source: Google Ngram Viewer )