anecdote vs improvisation

anecdote

noun
  • A short account of a real incident or person, often humorous or interesting. 

  • A previously untold secret account of an incident. 

  • An account which supports an argument, but which is not supported by scientific or statistical analysis. 

verb
  • To tell anecdotes (about). 

improvisation

noun
  • That which is improvised; an impromptu. 

  • The act or art of composing and making music, poetry, and the like, extemporaneously 

  • Musical technique, characteristic of blues music. 

  • The act of improvising, acting or going about something without planning ahead 

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