discordance vs point of contention

discordance

noun
  • A state of being discordant; disagreement, inconsistency. 

  • The presence of a specific genetic trait in only one of a set of clones (or identical twins). 

  • Discordance of sounds; dissonance. 

point of contention

noun
  • A matter that forms the basis of a disagreement, struggle, etc. 

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