hard rock vs modern

hard rock

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

modern

noun
  • Someone who lives in modern times. 

adj
  • Pertaining to the modern period (c.1800 to contemporary times), particularly in academic historiography. 

  • Pertaining to a current or recent time and style; not ancient. 

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