viola vs violin

viola

noun
  • A stringed instrument of the violin family, somewhat larger than a violin, played under the chin, and having a deeper tone. 

  • A 10-string steel-string acoustic guitar, used in Brazilian folk music. 

  • A person who plays the viola. 

  • An organ stop having a similar tone. 

  • A berimbau viola, the smallest member of the berimbau used in capoeira music. 

  • Any of several flowering plants, of the genus Viola, including the violets and pansies. 

violin

noun
  • Any instrument of the violin family, always inclusive of violins, violas, and cellos and sometimes further including the double bass. 

  • A small unfretted stringed instrument with four strings tuned (lowest to highest) G-D-A-E, usually held against the chin and played with a bow. 

  • The position of a violinist in an orchestra or group. 

verb
  • To play on, or as if on, a violin. 

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