music vs rock music

music

noun
  • A guide to playing or singing a particular tune; sheet music. 

  • A series of sounds organized in time, usually employing some combination of melody, harmony, tempo, rhythm etc. usually to convey a mood. 

  • An art form, created by organizing of pitch, rhythm, and sounds made using musical instruments and sometimes singing. 

  • Any pleasing or interesting sounds. 

  • Electronic signal jamming. 

verb
  • To seduce or entice with music. 

rock music

noun
  • A broad genre of popular music, including especially those styles ultimately derived from rock and roll, employing electrical amplification, heavy use of guitars, 4/4 time with strong percussive rhythm on beats two and four (backbeat), and usually themes of bold wildness, rebellion, and sexuality. 

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