boogie-woogie vs hard rock

boogie-woogie

noun
  • A style of blues piano music. 

  • A style of swing dance. 

hard rock

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

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