double bass vs kit violin

double bass

noun
  • The largest stringed instrument of the violin family. 

  • The deepest of all male voices. 

kit violin

noun
  • A very small long-necked violin that came in a variety of shapes and configurations, meant to be carried in a pocket and intended for dancing instructors to carry to accompany their students. 

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