cry the blues vs sob

cry the blues

verb
  • To complain, especially in order to obtain sympathy for one's own purportedly sad situation. 

  • To sing in the style of blues music. 

sob

verb
  • To say (something) while sobbing. 

  • To soak. 

  • To weep with convulsive gasps. 

noun
  • A cry with a short, sudden expulsion of breath. 

  • sound of sob 

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