gusle vs vielle

gusle

noun
  • A single-stringed lute-like stringed instrument with a bowl-shaped body, held vertically in the lap and played a bow, originating among the Slavic peoples in the Balkans, especially in the Dinarides region. 

vielle

noun
  • A medieval stringed instrument similar to a violin. 

  • The hurdy-gurdy. 

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