finale vs initiation

finale

noun
  • The chronological conclusion of a series of narrative works. 

  • The grand end of something, especially a show or piece of music. 

initiation

noun
  • The first step of transcription or of transduction. 

  • The form or ceremony by which a person is introduced into any society; mode of entrance into an organized body; especially, the rite of admission into a secret society or order. 

  • The act of initiating, or the process of being initiated or introduced 

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