cry the blues vs mourn

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. 

mourn

verb
  • To utter in a sorrowful manner. 

  • To express sadness or sorrow for; to grieve over (especially a death). 

  • To wear mourning. 

noun
  • Sorrow, grief. 

  • A ring fitted upon the head of a lance to prevent wounding an adversary in tilting. 

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