balladry vs versification

balladry

noun
  • ballads considered as a group; also, the sharing (transmission), making and performing of ballads, ballads as an activity, as a tradition, as a body of work, as a craft, as implying a community of singers, makers and lovers of ballads. 

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 balladry and versification occurred in a corpus of books? (source: Google Ngram Viewer )