author vs balladist

author

noun
  • The originator or creator of a work, especially of a literary composition. 

  • Someone who writes books for a living. 

verb
  • To create a work as its author. 

balladist

noun
  • One who composes or performs ballads. 

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