hard rock vs silence

hard rock

noun
  • A rock music genre marked by a heavy regular beat, high amplification, and usually frenzied performances. 

silence

intj
  • Be silent. 

verb
  • To repress the expression of something. 

  • To suppress criticism, etc. 

  • To block gene expression. 

  • To murder. 

  • To make (someone or something) silent. 

noun
  • deadly silence 

  • The act of refraining from speaking. 

  • The absence of any sound. 

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