front line vs new wave

front line

noun
  • A low level. 

  • attack, collectively the attackers or forwards. 

  • A site of a conflict, effort, or controversial matter of any kind. 

  • A front, or a boundary between opposing positions. 

  • The site of interaction with outsiders, such as customers. 

new wave

adj
  • Representing the latest and most advanced style. 

noun
  • An alternative and broad pop and rock music genre that existed during the late 1970s and the early to mid-1980s, incorporating punk sensibilities and/or other forms of music, but made with more accessibility. 

How often have the words front line and new wave occurred in a corpus of books? (source: Google Ngram Viewer )