classical guitar vs guitar

classical guitar

noun
  • A type of flat-tabled guitar of Spanish origin used primarily for Western classical music, flamenco, and Latin American music, with six nylon (formerly gut) strings, usually played with the fingers rather than with a plectrum. 

guitar

noun
  • A stringed musical instrument, of European origin, usually with a fretted fingerboard and six strings, played with the fingers or a plectrum (guitar pick). 

  • Any type of musical instrument of the lute family, characterized by a flat back, along with a neck whose upper surface is in the same plane as the soundboard, with strings along the neck and parallel to the soundboard. 

verb
  • To play the guitar. 

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