diva vs singer

diva

noun
  • Any female celebrity, usually a well known singer or actress. 

  • A person who may be considered or who considers herself (or by extension himself) much more important than others, has high expectations of others and who is extremely demanding and fussy when it comes to personal privileges. 

singer

noun
  • A person who sings, often professionally. 

  • A machine for singeing cloth. 

  • A person who, or device which, singes. 

  • dance figure with a fixed structure, sung by a caller, or a piece of music with that structure. 

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