Birdie vs Chorus

Birdie

name
  • A female given name from English. 

  • An effective or child's term for any (small) bird. (1999: Oxford Dictionary of Slang, p. 130) 

Chorus

name
  • A song performed by the singers of such a group. 

  • A group of singers and dancers in a theatrical performance or religious festival who commented on the main performance in speech or song. 

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