lyrics vs versification

lyrics

noun
  • The words to a song (or other vocal music). 

versification

noun
  • The act, art, or practice of composing poetic verse; the construction or measure of verse or poetry; metrical composition. 

  • The process by which the books of the Bible were divided into verses; a particular way of dividing biblical books into verses 

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