bagpipes vs churr

bagpipes

noun
  • A musical wind instrument of Celtic origin, possessing a flexible bag inflated by bellows, a double-reed melody pipe and up to four drone pipes; any aerophone that produces sound using air from a reservoir to vibrate enclosed reeds. 

churr

noun
  • A low vocal sound made by some birds. 

verb
  • To make the low vocal sound of some birds. 

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