Chorus vs Ivory

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. 

Ivory

name
  • A female given name from English. 

  • A surname from Old French. 

  • A male given name from English. 

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