cello vs rebec

cello

noun
  • A large unfretted stringed instrument of the violin family with four strings tuned (lowest to highest) C-G-D-A and an endpin to support its weight, usually played with a bow. 

  • cellophane 

rebec

noun
  • An early three-stringed instrument, somewhat like a simple violin only pear shaped, played with a bow and used in Medieval and the early Renaissance eras. 

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