guitar pick vs strum

guitar pick

noun
  • A small piece of plastic, metal, ivory, etc., for plucking the strings of a guitar, lyre, mandolin, etc. 

strum

noun
  • The sound made by playing various strings of a stringed instrument simultaneously. 

  • The act of strumming. 

verb
  • To play (a guitar or other stringed instrument) using various strings simultaneously. 

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