disagreement vs unison

disagreement

noun
  • A condition of not agreeing or concurring. 

  • An argument or debate. 

unison

noun
  • A sound or note having the same pitch as another, especially when used as the base note for an interval; a unison string. 

  • The state of being in harmony or agreement; harmonious agreement or togetherness, synchronisation. 

  • Identical pitch between two notes or sounds; the simultaneous playing of notes of identical pitch (or separated by one or more octaves). 

  • Two or more voices speaking the same words together. 

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