ballad vs fiction

ballad

noun
  • A kind of narrative poem, adapted for recitation or singing; especially, a sentimental or romantic poem in short stanzas. 

  • A slow romantic song. 

verb
  • To compose or sing ballads. 

fiction

noun
  • A verbal or written account that is not based on actual events (often intended to mislead). 

  • Literary type using invented or imaginative writing, instead of real facts, usually written as prose. 

  • A legal fiction. 

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