Boo vs Chorus

Boo

name
  • The Boko language. 

  • A community in Nacka, Stockholm, central Sweden. 

Chorus

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

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

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