complain vs falsetto

complain

verb
  • To make a formal accusation or bring a formal charge. 

  • To creak or squeak, as a timber or wheel. 

  • To express feelings of pain, dissatisfaction, or resentment. 

falsetto

verb
  • To sing or utter in falsetto. 

noun
  • A person who sings in falsetto. 

  • The "false" (singing) voice in any human, usually airy and lacking a purity of vowels; created by utilizing the next highest vocal folds above those used for speech and normal range singing. It is commonly confused with the head voice register. 

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