folk song vs music

folk song

noun
  • folk music 

  • A song, in any folk style, originating among ordinary people, usually non-professional musicians, and handed down by oral tradition. 

  • A song in the style of folk music, a modern genre of popular 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. 

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