cantor vs chorister

cantor

noun
  • singer, especially someone who takes a special role of singing or song leading at a ceremony 

  • A prayer leader in a Jewish service; a hazzan 

chorister

noun
  • A singer in a choir. 

  • A director or leader of a choral group. 

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