hard rock vs popular

hard rock

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

popular

adj
  • Liked by many people; generally pleasing, widely admired. 

  • Common among the general public; generally accepted. 

  • Pertaining to or deriving from the people or general public. 

  • Adapted to the means of the common people; cheap. 

  • Concerning the people; public. 

  • Aimed at ordinary people, as opposed to specialists etc.; intended for general consumption. 

noun
  • A person who is popular, especially at a school. 

  • An inexpensive newspaper with wide circulation. 

  • A member of the Populares 

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