entertainer vs opera singer

entertainer

noun
  • Someone who puts on a show for the entertainment or enjoyment of others. 

  • A person who entertains others, esp. as a profession, as a singer, actor, presenter, dancer, musician, magician, comedian, etc. 

opera singer

noun
  • Someone who sings opera professionally. 

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