rapport vs simultaneity

rapport

noun
  • Relation; proportion; conformity. 

  • A relationship of mutual trust and respect. A close and harmonious relationship in which the people or groups concerned understand each other's feelings or ideas and communicate well. 

simultaneity

noun
  • The quality or state of being simultaneous; simultaneousness. 

  • More than one complete musical texture occurring at the same time. This first appeared in the music of Charles Ives, and is common in the music of Conlon Nancarrow, and others. 

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