protagonist vs songbird

protagonist

noun
  • An advocate or champion of a cause or course of action. 

  • The main character, or one of the main characters, in any story, such as a literary work or drama. 

  • A leading person in a contest; a principal performer. 

songbird

noun
  • Any bird in the passerine suborder Passeri, which are distinguished by a more sophisticated vocal apparatus 

  • A bird having a melodious song or call. 

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