piano vs yangqin

piano

noun
  • a percussive keyboard musical instrument, usually ranging over seven octaves, with white and black colored keys, played by pressing these keys, causing hammers to strike strings 

verb
  • To play the piano. 

  • To move (the fingers) up and down on, similar to the motions of a pianist playing the piano. 

  • To become softer and less intense. 

  • To equip with a piano. 

adj
  • Gentle, soft, subdued. 

  • Soft, quiet. 

adv
  • softly, as a musical direction (abbreviated to p. in sheet music) 

yangqin

noun
  • A Chinese musical instrument, a hammered dulcimer traditionally fitted with bronze strings. 

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